Palmer v Western Australia

HIGH COURT OF AUSTRALIA

KIEFEL CJ,
GAGELER, KEANE, GORDON AND EDELMAN JJ

CLIVE FREDERICK PALMER & ANOR  PLAINTIFFS

AND

THE STATE OF WESTERN AUSTRALIA & ANOR         DEFENDANTS

Palmer v Western Australia

[2021] HCA 5

Date of Hearing: 3 & 4 November 2020
Date of Order: 6 November 2020
Date of Publication of Reasons: 24 February 2021

B26/2020

ORDER

The questions stated for the opinion of the Full Court in the special case filed on 22 September 2020 be answered as follows:

(a)Are the Quarantine (Closing the Border) Directions (WA) and/or the authorising Emergency Management Act 2005 (WA) invalid (in whole or in part, and if in part, to what extent) because they impermissibly infringe s 92 of the Constitution?

Answer:

On their proper construction, ss 56 and 67 of the Emergency Management Act 2005 (WA) in their application to an emergency constituted by the occurrence of a hazard in the nature of a plague or epidemic comply with the constitutional limitation of s 92 of the Constitution in each of its limbs.

The exercise of the power given by those provisions to make paras 4 and 5 of the Quarantine (Closing the Border) Directions (WA) does not raise a constitutional question.

No issue is taken as to whether the Quarantine (Closing the Border) Directions (WA) were validly authorised by the statutory provisions so that no other question remains for determination by a court.

(b)Who should pay the costs of the special case?

Answer:

The plaintiffs.

Representation

P J Dunning QC with R Scheelings and P J Ward for the plaintiffs (instructed by Jonathan Shaw)

J A Thomson SC, Solicitor-General for the State of Western Australia, with J D Berson for the defendants (instructed by State Solicitor's Office (WA))

P J F Garrisson SC, Solicitor-General for the Australian Capital Territory, with H Younan SC and A M Hammond for the Attorney-General for the Australian Capital Territory, intervening (instructed by ACT Government Solicitor)

M E O'Farrell SC, Solicitor-General for the State of Tasmania, with S K Kay for the Attorney-General for the State of Tasmania, intervening (instructed by Solicitor-General of Tasmania)

G A Thompson QC, Solicitor-General of the State of Queensland, with F J Nagorcka and K J E Blore for the Attorney-General of the State of Queensland, intervening (instructed by Crown Law (Qld))

M J Wait SC, Solicitor-General for the State of South Australia, with F J McDonald for the Attorney-General for the State of South Australia, intervening (instructed by Crown Solicitor's Office (SA))

P J Hanks QC with P P Thiagarajan and T M Wood for the Attorney-General for the State of Victoria, intervening (instructed by Victorian Government Solicitor's Office)

T J Moses with L S Peattie for the Attorney-General for the Northern Territory, intervening (instructed by Solicitor for the Northern Territory)

Notice:  This copy of the Court's Reasons for Judgment is subject to formal revision prior to publication in the Commonwealth Law Reports.

CATCHWORDS

Palmer v Western Australia

Constitutional law (Cth) – Freedom of interstate trade, commerce, and intercourse – Where s 56 of Emergency Management Act 2005 (WA) ("EM Act") empowered Minister to declare state of emergency – Where s 67 empowered authorised officer to direct or prohibit movement of persons into emergency area – Where Minister for Emergency Services declared state of emergency in Western Australia in respect of COVID-19 pandemic – Where State Emergency Coordinator issued Quarantine (Closing the Border) Directions (WA) ("Directions") – Where paras 4 and 5 of Directions prohibited persons from entering Western Australia unless exempt traveller – Whether EM Act or Directions impermissibly infringed constitutional limitation in s 92 of Constitution – Whether infringement determined by reference to authorising provisions of EM Act – Whether provisions of EM Act imposed impermissible burden on interstate trade, commerce or intercourse – Whether exercise of power to make Directions raised constitutional question.

Words and phrases – "burden", "COVID-19", "differential", "discrimination", "emergency", "emergency management", "freedom of interstate trade, commerce, and intercourse", "hazard", "intercourse", "interstate movement", "plague or epidemic", “protectionist”, "reasonable necessity", "state of emergency", "structured proportionality", "trade and commerce".

Constitution, s 92.
Emergency Management Act 2005 (WA), ss 56, 58, 67, 72A.
Quarantine (Closing the Border) Directions (WA), paras 4, 5, 27.

1. KIEFEL CJ AND KEANE J. On 11 March 2020 the World Health Organization declared COVID‑19 a pandemic. On 15 March 2020 the Minister for Emergency Services for Western Australia declared a state of emergency with effect from 16 March 2020 in respect of the pandemic pursuant to s 56 of the Emergency Management Act 2005 (WA) ("the EM Act"). The area to which the state of emergency declaration was to apply was Western Australia. The Commissioner of Police, as the holder of the office of State Emergency Coordinator[1], issued the Quarantine (Closing the Border) Directions (WA) ("the Directions"), which took effect from 5 April 2020.

   [1]EM Act, s 10.

   The EM Act

2. Section 56 of the EM Act, in relevant part, provides:

   "(1)The Minister may, in writing, declare that a state of emergency exists in the whole or in any area or areas of the State.

   (2)The Minister must not make a declaration under this section unless the Minister –

   (a)has considered the advice of the State Emergency Coordinator; and

   (b)is satisfied that an emergency has occurred, is occurring or is imminent; and

   (c)is satisfied that extraordinary measures are required to prevent or minimise –

   (i)loss of life, prejudice to the safety, or harm to the health, of persons or animals".

3. An "emergency" is defined[2] to mean "the occurrence or imminent occurrence of a hazard which is of such a nature or magnitude that it requires a significant and coordinated response". The meaning of "hazard" includes "a plague or an epidemic".

   [2]EM Act, s 3.

4. A state of emergency declaration (an "emergency declaration") remains in force for three days after the time it first has effect if it is not extended by a declaration made by the Minister under s 58[3]. Section 58(4) relevantly provides that an emergency declaration may be extended for a period not exceeding 14 days. It may be further extended from time to time[4]. The original emergency declaration of 15 March 2020 was so extended and further extended and remained current at the time of the hearing.

   [3]EM Act, s 57, s 58(1).

   [4]EM Act, s 58(1).

5. There is no dispute that the Directions were authorised by the EM Act. The EM Act contains general powers such as those in s 72A(2), whereby an authorised officer may "take, or direct a person or a class of person to take, any action that the officer considers is reasonably necessary to prevent, control or abate risks associated with the emergency". But s 67 is most clearly directed to the border restrictions here in question. Its relevant parts were included in the EM Act as passed and provide:

   "For the purpose of emergency management during an emergency situation or state of emergency, a[n] ... authorised officer may do all or any of the following –

   (a)direct or, by direction, prohibit, the movement of persons, animals and vehicles within, into, out of or around an emergency area or any part of the emergency area".

6. The State Emergency Coordinator (the Commissioner of Police) is an authorised officer[5]. The emergency area according to the emergency declaration is Western Australia. The words "emergency management", which appear in s 67, mean "the management of the adverse effects of an emergency" and relevantly include "prevention" ("the mitigation or prevention of the probability of the occurrence of, and the potential adverse effects of, an emergency") and "response" ("the combating of the effects of an emergency, provision of emergency assistance for casualties, reduction of further damage, and help to speed recovery")[6]. It is an offence to fail to comply with a direction[7].

   [5]EM Act, s 3 (definition of "authorised officer").

   [6]EM Act, s 3 (definition of "emergency management" (a) and (c)).

   [7]EM Act, s 86(1).

7. The effect of the Directions is to close the border of Western Australia to all persons from any place unless they were the subject of exemption under the Directions. Paragraph 4 of the Directions provides that "[a] person must not enter Western Australia unless the person is an exempt traveller". The term "exempt traveller", defined in para 27, refers to a person falling within certain categories such as officials or personnel concerned with national and State security and governance, persons providing health services or persons whose entry is approved on compassionate grounds, and who complies with any specified terms or conditions. Paragraph 5 of the Directions states that in certain circumstances even exempt travellers must not enter Western Australia, for example where they have certain defined symptoms or have been identified as a close contact with a person who has COVID-19.

8. At the time this matter was heard, the Chief Health Officer for Western Australia had given advice to the Premier of Western Australia concerning easing of the border controls. The Premier and the Minister for Health had announced publicly that the "existing hard border exemption system will be removed and replaced with an updated nationwide health-based threshold that allows for safe travel into Western Australia" from interstate on conditions. Subject to the latest available health advice, it was planned to enact the new interstate border measures under the EM Act on 14 November 2020. The plaintiffs nevertheless proceeded with the hearing of their matter because, they contended, the Premier's announcement was highly conditional and there was an important, justiciable controversy to be resolved.

   The plaintiffs' challenge

9. The first sentence of s 92 of the Constitution provides that:

   "On the imposition of uniform duties of customs, trade, commerce, and intercourse among the States, whether by means of internal carriage or ocean navigation, shall be absolutely free."

10. The first plaintiff is a resident of the State of Queensland and the Chairman and Managing Director of the second plaintiff. He travels to and from Western Australia for purposes associated with the second plaintiff and for other purposes, and whilst in Perth stays at a residence maintained by the second plaintiff. He has not, to his knowledge, suffered any symptoms of COVID-19. His application to enter Western Australia as an "exempt traveller" was refused.

11. The second plaintiff is a company with interests in iron ore projects in Western Australia and is engaged in litigation and arbitration in that State. It has offices and personnel in Perth, where many of its records are held. Other personnel, including professional advisers who would normally work in both Brisbane and Perth, are likewise unable to enter Western Australia. It contended that its business and other interests are harmed or inhibited.

12. In proceedings commenced on 25 May 2020 in the original jurisdiction of this Court the plaintiffs claim a declaration that "either the authorising Act and/or the Directions are invalid, either wholly or in part … by reason of s 92 of the Constitution". The plaintiffs' claims to invalidity and the particulars provided of them refer to the Directions and their effects.

13. The plaintiffs claim that the Directions impose an effective burden on the freedom of intercourse among the Australian people in the several States by prohibiting cross-border movement of persons, backed by a criminal sanction. Alternatively, they allege that the freedom of trade and commerce guaranteed by s 92 is contravened because the Directions impose an effective discriminatory burden with protectionist effect.

14. The defendants, the State of Western Australia and the Commissioner of Police for Western Australia, deny the plaintiffs' allegations. In their defence they plead that s 67 and other provisions of the EM Act do not have the purpose of economically protecting the State of Western Australia, rather they have the legitimate purpose of protecting the population of Western Australia against risks arising from emergency situations. The continuation in force of the Directions, pursuant to the EM Act, does not have a protectionist purpose and is reasonably necessary to achieve, and is compatible with, the legitimate purpose of protecting the Western Australian population against the health risks of COVID-19 where there are no other equally effective means available to achieve that purpose which would impose a lesser burden on interstate trade or commerce. Likewise, it is pleaded that intercourse among the States, whether by movement or communication, is prevented only to the extent that is reasonably necessary and that there are no other, equally effective means which impose a lesser burden on that intercourse.

15. No agreement could be reached between the parties as to the facts necessary to determine the defendants' claim of the reasonable need for and efficacy of the measures contained in the Directions, which would have enabled an earlier hearing of the matter by this Court. By order made on 16 June 2020, that issue was remitted to the Federal Court of Australia for hearing and determination pursuant to s 44 of the Judiciary Act 1903 (Cth). On 25 August 2020 Rangiah J of that Court made findings of fact.

    The findings on remitter

16. After hearing evidence from a number of witnesses, including the Chief Health Officer for Western Australia and experts in public health medicine, epidemiology, and infectious diseases, Rangiah J found that certain facts relating to COVID‑19 and SARS-CoV-2, which had been pleaded by the defendants as particulars of the justification for the Directions, had been proved[8].

    [8]Palmer v Western Australia [No 4] [2020] FCA 1221 at [363]-[364].

17. The facts so found included the following. COVID‑19 is a disease caused by the coronavirus SARS‑CoV‑2. Clinical and epidemiological knowledge about them is relatively uncertain, their being a new pathogen and disease. SARS-CoV-2 may be transmitted by a person who is asymptomatic and unaware that they have the disease. Where there is community transmission of SARS-CoV-2 its natural growth rate is exponential and must be minimised through certain measures. The risk of community transmission is substantially increased if measures of the kind contained in the Directions are removed. There are no known testing measures which are themselves sufficient to prevent community transmission.

18. The consequences of community transmission of SARS‑CoV‑2 and the development of COVID‑19 are substantial, including the increased risk of death – particularly for members of the population who are over 70 years of age, members of the population with pre-existing medical conditions or members of the Aboriginal or Torres Strait Islander population – and the risk that the hospital system in Western Australia will be unable to cope. There is no known vaccine, and no treatment presently available to mitigate the risks of severe medical outcomes or mortality for a person who contracts COVID‑19.

19. At the conclusion of his detailed reasons his Honour summarised the overall findings he had made[9]. His Honour considered that the risk to the health of the Western Australian population is a function of two factors: the probability that COVID‑19 would be imported into the population and the seriousness of the consequences if it were imported. Whilst the existing border restrictions do not eliminate the potential for importation of COVID‑19 from other States or Territories, because they allow "exempt travellers" to enter Western Australia, they have been effective to a "very substantial extent" to reduce the probability of COVID‑19 being imported into Western Australia from interstate.

    [9]Palmer v Western Australia [No 4] [2020] FCA 1221 at [366].

20. His Honour explained that the uncertainties involved in predicting all relevant factors are such that the probability of persons infected with COVID-19 entering Western Australia in the hypothetical situation where border restrictions are removed cannot be accurately quantified. His Honour therefore undertook qualitative assessments of the probability that persons infected with COVID‑19 would enter Western Australia if the border restrictions were completely removed. His Honour assessed the risk of persons coming from Australia as a whole and from Victoria as high; from New South Wales as moderate; from South Australia, the Australian Capital Territory and the Northern Territory as low; from Tasmania as very low; and from Queensland as uncertain, due to the recent reintroduction of the disease in that State. It is evident that there have been some changes in the circumstances of the States since his Honour's assessments. The plaintiffs contended that Queensland would now be regarded as a low, rather than uncertain, risk and the situation in Victoria has changed. It will not be necessary to come to a concluded view about these contentions. They are not determinative of any issue in the proceedings.

21. His Honour considered that if persons entered the Western Australian community whilst infectious there would be a high probability that the virus would be transmitted into the Western Australian population and at least a moderate probability that there would be uncontrolled outbreaks. If there were uncontrolled outbreaks, the consequences would include the risk of death and hospitalisation, particularly for the vulnerable groups mentioned above. In a worst‑case scenario, the health consequences could be "catastrophic".

22. His Honour observed that Western Australia had not had any cases of community transmission since 12 April 2020 as a result of the combination of the border restrictions and other measures. Western Australia could not safely manage the number of people in hotel quarantine if it were sought to replace the border restrictions with mandatory hotel quarantine for all entrants to the State. If the restrictions were replaced by a suite of measures including exit and entry screening, the wearing of face masks on aeroplanes and for 14 days after entry into the State, and testing at intervals, they would be less effective than the border restrictions in preventing the importation of COVID‑19. A combination of that suite of measures together with a "hotspot" regime, involving either quarantining or banning persons entering from designated areas in the other States or Territories, would also be less effective than the border restrictions.

23. His Honour concluded that in view of the uncertainties involved in determining the probability that COVID‑19 would be imported into Western Australia from elsewhere in Australia, and the potentially serious consequences if it were imported, "a precautionary approach should be taken to decision‑making about the measures required for the protection of the community".

    The questions reserved

24. The parties subsequently agreed a Special Case pursuant to which the following questions were stated for the opinion of the Full Court of this Court:

    "(a)Are the Quarantine (Closing the Border) Directions (WA) and/or the authorising Emergency Management Act 2005 (WA) invalid (in whole or in part, and if in part, to what extent) because they impermissibly infringe s 92 of the Constitution?

    (b)Who should pay the costs of the special case?"

25. On 6 November 2020 the Court answered the questions as follows:

    "(a)On their proper construction, ss 56 and 67 of the Emergency Management Act 2005 (WA) in their application to an emergency constituted by the occurrence of a hazard in the nature of a plague or epidemic comply with the constitutional limitation of s 92 of the Constitution in each of its limbs.

    The exercise of the power given by those provisions to make paras 4 and 5 of the Quarantine (Closing the Border) Directions (WA) does not raise a constitutional question.

    No issue is taken as to whether the Quarantine (Closing the Border) Directions (WA) were validly authorised by the statutory provisions so that no other question remains for determination by a court.

    (b)The plaintiffs."

26. These are our reasons for joining in the answers given.

    What s 92 precludes

27. Although it is sometimes convenient to refer to s 92 as having two limbs – the trade and commerce limb and the intercourse limb – the words "trade, commerce, and intercourse" are stated in the section as a composite expression. The observation that until Cole v Whitfield[10] decisions of this Court did not treat the two limbs as substantially different[11] is clearly correct. Section 92 has been regarded as concerned with all kinds of movement across State borders[12].

    [10](1988) 165 CLR 360.

    [11]APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322 at 456 [400] per Hayne J.

    [12]Bank of New South Wales v The Commonwealth ("the Bank Nationalisation Case") (1948) 76 CLR 1 at 381-382 per Dixon J.

    Cole v Whitfield

28. It is well understood that Cole v Whitfield marked a turning point in s 92 jurisprudence. Prior to that decision, s 92 had been regarded by many as guaranteeing the right of individuals to engage in trade, commerce and intercourse. The broad effects of such an approach were mitigated by the "criterion of operation" doctrine, by which s 92 was applied only to laws directed to an essential attribute of interstate trade, commerce or intercourse[13]. These interpretations were rejected in Cole v Whitfield[14], where the Court instead adopted an approach which had regard to the character of a law and its effects upon freedom of interstate trade and commerce.

    [13]See Gratwick v Johnson (1945) 70 CLR 1 at 20 per Dixon J.

    [14](1988) 165 CLR 360 at 400-402.

29. In Cole v Whitfield[15] the Court said that the guarantee in s 92, that interstate trade, commerce and intercourse be "absolutely free", was not to be taken literally. The section should not be construed as precluding an exercise of legislative power which would impose any barrier or restriction on interstate trade or commerce[16] or interstate intercourse[17]. This view of s 92 had consistently been applied in cases which preceded Cole v Whitfield[18] and it was to be confirmed in subsequent cases[19].

    [15](1988) 165 CLR 360 at 394.

    [16]Cole v Whitfield (1988) 165 CLR 360 at 398.

    [17]Cole v Whitfield (1988) 165 CLR 360 at 393.

    [18]See, eg, R v Smithers; Ex parte Benson (1912) 16 CLR 99 at 110 per Barton J; Gratwick v Johnson (1945) 70 CLR 1 at 13 per Latham CJ.

    [19]Nationwide News Pty Ltd v Wills (1992) 177 CLR 1 at 56 per Brennan J; Australian Capital Television Pty Ltd v The Commonwealth (1992) 177 CLR 106 at 192-193 per Dawson J; APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322 at 394 [178] per Gummow J.

30. Cole v Whitfield explained that so far as s 92 concerned interstate trade and commerce it should be understood to preclude particular types of burdens on that trade or commerce, such as discriminatory burdens of a protectionist kind. It held that a law will relevantly discriminate if on its face it subjects interstate trade or commerce to a disability or disadvantage or if the operation of the law in fact produces such a result[20]. The freedom which s 92 guarantees is freedom from discriminatory burdens which have a protectionist effect[21].

    [20]Cole v Whitfield (1988) 165 CLR 360 at 394, 399.

    [21]Cole v Whitfield (1988) 165 CLR 360 at 394-395.

31. Discrimination in a legal sense involves a comparison of relative equals by which one is treated unequally, or of unequals treated equally[22]. It involves the notion of effecting a disadvantage to one[23]. So understood, for the purposes of s 92, a law discriminates when it treats interstate trade or commerce differently, as compared with intrastate trade or commerce, and effects a disadvantage to interstate trade or commerce.

    [22]See Castlemaine Tooheys Ltd v South Australia (1990) 169 CLR 436 at 478, 480 per Gaudron and McHugh JJ.

    [23]See Cole v Whitfield (1988) 165 CLR 360 at 399.

32. Not all laws which apply differentially so as to effect a discriminatory burden on interstate trade or commerce will infringe s 92. This possibility arises because the guarantee of freedom is not absolute, as previously discussed. Where such a law has a purpose which is evidently not of a protectionist kind it may, subject to a further requirement, be valid. The law in Cole v Whitfield was of this kind.

33. The respondents in Cole v Whitfield sought to bring crayfish to Tasmania from South Australia in the course of their interstate trade. The regulation in question prohibited the possession of crayfish less than a particular size in Tasmania. The law was seen as burdening interstate trade[24]. It was protectionist in purpose, but in a sense different from protectionism in trade. Its purpose was to protect and conserve a valuable natural resource, namely the stock of Tasmanian crayfish. This purpose, the Court said, is not a form of protection which gives a market advantage[25]. It concluded that the law could not be described as discriminatory and protectionist in the sense referable to s 92[26].

    [24]Cole v Whitfield (1988) 165 CLR 360 at 409.

    [25]Cole v Whitfield (1988) 165 CLR 360 at 409.

    [26]Cole v Whitfield (1988) 165 CLR 360 at 410.

34. The law's character as non-protectionist was not the only feature which saved it from invalidity. It is important to observe what was said in Cole v Whitfield concerning the need for the law. The Court said[27] that the extension of the prohibition beyond crayfish in Tasmania to imported interstate crayfish was necessary to prevent undersized crayfish being caught in Tasmanian waters. It was necessary because it was not possible for the State to undertake inspections other than random inspections and it could not determine which were and which were not Tasmanian crayfish. The Court may be understood to say that there was no real alternative to the prohibition on the sale and possession of undersized crayfish imported from interstate if the statutory objective of protection of crayfish stock in Tasmania was to be achieved.

    [27]Cole v Whitfield (1988) 165 CLR 360 at 409-410.

35. The purpose of the law in Cole v Whitfield may be contrasted with the purposes identified with respect to the laws in question in Castlemaine Tooheys Ltd v South Australia[28]. It was accepted in the joint judgment of Mason CJ, Brennan, Deane, Dawson and Toohey JJ[29] that there were "rational and legitimate" grounds for the apprehension that non‑refillable bottles contribute to the problem of litter and decrease the State's energy resources. If the legislative measures were "appropriate and adapted" to the resolution of those problems, their Honours said, they would be consistent with s 92. That would be so if the burden imposed on interstate trade "was incidental and not disproportionate" to the achievement of those purposes.

    [28](1990) 169 CLR 436.

    [29]Castlemaine Tooheys Ltd v South Australia (1990) 169 CLR 436 at 473-474.

36. The joint judgment in Castlemaine Tooheys concluded[30] that neither purpose provided "an acceptable explanation or justification for the differential treatment" given to the plaintiffs' products. Betfair Pty Ltd v Western Australia ("Betfair No 1")[31] was more clearly to articulate that the justification required of a discriminatory law which burdened interstate trade was that it be reasonably necessary to achieve its non-protectionist purpose.

    [30](1990) 169 CLR 436 at 477.

    [31](2008) 234 CLR 418.

    Betfair No 1 – justifying a burden

37. In the joint judgment in Betfair No 1[32] it was said that considerations to which weight must be given in an assessment of the "proportionality" between the differential burden imposed by the laws on an out-of-State producer, compared with the position of in‑State producers, suggested the application of a criterion of "reasonable necessity" to the law in question. In North Eastern Dairy Co Ltd v Dairy Industry Authority of NSW[33], Mason J had said that "[a]s the defendant has failed to show that the discriminatory mode of regulation selected is necessary for the protection of public health, it is in my judgment not a reasonable regulation of the interstate trade in pasteurized milk". That view of the matter, it was said in Betfair No 1, "should be accepted as the doctrine of the Court"[34]. It was, their Honours observed, consistent with the explanation given in Cole v Whitfield of the justification of the total prohibition on sale of undersized crayfish.

    [32](2008) 234 CLR 418 at 476-477 [101]-[103] per Gleeson CJ, Gummow, Kirby, Hayne, Crennan and Kiefel JJ.

    [33](1975) 134 CLR 559 at 608.

    [34](2008) 234 CLR 418 at 477 [103].

38. The first plaintiff in Betfair No 1 conducted a betting exchange in Tasmania through the use of the internet and telephone call centres. Legislation in Western Australia made it an offence for a person to use a betting exchange and an offence to make available information as to the field of a horse or greyhound race in Western Australia, without authorisation. The first-mentioned law effected a discriminatory burden of a protectionist kind; the second operated to the competitive disadvantage of interstate operators such as the first plaintiff, imposing a discriminatory burden of a protectionist kind[35].

    [35]Betfair No 1 (2008) 234 CLR 418 at 481 [118], [120].

39. Western Australia argued that the measures were necessary to protect the integrity of the racing industry in that State. In the section of the joint judgment headed "Acceptable explanation or justification?"[36], it was said that even allowing for the presence of some such threat to the racing industry, to which the legislative provisions might be directed, the prohibitions could not be justified. They could not be justified if there was the prospect of an alternative method of countering the threat and that method was "effective but non‑discriminatory regulation"[37]. The joint judgment accepted that different legislative measures taken by Tasmania with respect to betting exchanges fulfilled these criteria. The prohibitions effected by the legislation in Western Australia could not therefore be said to be "necessary". Their Honours concluded that "the prohibitory State law is not proportionate; it is not appropriate and adapted to the propounded legislative object"[38].

    [36]Betfair No 1 (2008) 234 CLR 418 at 479 [110].

    [37]Betfair No 1 (2008) 234 CLR 418 at 479 [110].

    [38]Betfair No 1 (2008) 234 CLR 418 at 479-480 [109]-[112].

    Interstate movement – a distinction?

40. The guarantee of freedom of interstate intercourse may be taken to refer to both physical movement and communication across State borders, and to be directed to the circumstance where borders are used as barriers to freedom of movement between States. Until now there has been no occasion since Cole v Whitfield fully to consider the distinction drawn in that case between this freedom and that respecting interstate trade and commerce.

41. Consistently with the rejection of the individual rights approach with respect to interstate trade and commerce, the Court in Cole v Whitfield regarded s 92 as effecting a limit on laws which may be made affecting those subjects. But in discussion about interstate intercourse it took quite a different approach. It regarded the guarantee of freedom of interstate movement as extending to a "guarantee of personal freedom 'to pass to and fro among the States without burden, hindrance or restriction'"[39], drawing in part on what had been said by Starke J in Gratwick v Johnson[40].

    [39]Cole v Whitfield (1988) 165 CLR 360 at 393.

    [40](1945) 70 CLR 1 at 17.

42. It is understandable why it was thought necessary in Cole v Whitfield to make plain that s 92 was not intended as a protection of individual interstate traders. It was concerned more generally with effects on interstate trade and commerce. It is not entirely clear why it was thought necessary to retain the notion of a right of persons to pass between the States. It was not fully explained. The matter in Cole v Whitfield engaged only the trade and commerce limb. Having distinguished the intercourse limb, no further discussion about it was engaged in. It was put to one side.

43. A basis given in Cole v Whitfield for distinguishing between the two limbs was that some forms of interstate intercourse are likely of their nature to be immune from legislative or executive interference. If a like immunity were accorded to trade and commerce "anarchy would result"[41]. Since s 92 had never been understood to guarantee freedom to this extent, there is no reason, the Court said, for insisting on a strict correspondence between the freedoms[42].

    [41]Cole v Whitfield (1988) 165 CLR 360 at 393.

    [42]Cole v Whitfield (1988) 165 CLR 360 at 393-394.

44. Some support for the distinction drawn in Cole v Whitfield was said to arise from history. It may be accepted that interstate movement was not adopted at a later point in the course of the Convention Debates and that it was no mere afterthought[43]. But as earlier observed[44], prior decisions of this Court respecting s 92 did not meaningfully distinguish between the two limbs. The nature of the guarantee provided with respect to them was not regarded as different. In its application to either of the freedoms it was not regarded as absolute. This hardly suggests that interstate movement should be favoured with some kind of immunity.

    [43]Cole v Whitfield (1988) 165 CLR 360 at 387-388.

    [44]At [27] above.

45. The distinction drawn in Cole v Whitfield has the obvious consequence that guarantees of freedoms appearing in the one provision of the Constitution are to be treated differently. This might suggest incoherence, which is not regarded as a desirable outcome for constitutional interpretation. More importantly, the distinction drawn in Cole v Whitfield is not consistent with a modern approach to constitutional interpretation. The distinction does not derive any support from the text of s 92. The text does not provide a basis for treating one of three elements of the composite expression "trade, commerce, and intercourse among the States" as connoting or requiring that some different test be applied to them[45].

    [45]APLALtd v Legal Services Commissioner (NSW) (2005) 224 CLR 322 at 456-457 [402] per Hayne J.

46. Cole v Whitfield did not discuss whether the approach there taken to discriminatory burdens imposed by a law on freedom of interstate trade and commerce, shorn of its economic aspects, might be applied to the freedom of interstate intercourse. It is that prospect which should now be addressed.

    Interstate movement and discrimination

47. It must be accepted that protectionist discrimination and its economic effects are not likely to be relevant to interstate movement. Further, a law which differentiates between interstate movement and intrastate movement may not advantage the latter to any real extent. Nevertheless it is possible to compare the effects of a law on interstate movement with its effects on intrastate movement. That is to say the test of discrimination which is applied to the trade and commerce limb could be applied to the intercourse limb. Moreover, as Hayne J observed in APLA Ltd v Legal Services Commissioner (NSW)[46], the text of s 92 does not suggest that some different test be applied to the two limbs.

    [46](2005) 224 CLR 322 at 456-457 [402].

48. Queensland, intervening, submitted that a law may be taken to burden freedom of interstate movement for the purposes of s 92 where it discriminates against that movement[47]. Discrimination should be required for both limbs of s 92 as a matter of construction, because textually s 92 does not disclose a basis for requiring discrimination for one limb and not the other; the intercourse limb may otherwise largely subsume the trade and commerce limb; and general laws that burden interstate movement may be held invalid. Queensland submitted that a law which burdens interstate movement should be subject to a requirement of justification, in the same way as is required where interstate trade and commerce is burdened. These submissions should be accepted.

    [47]Referring to Nationwide News Pty Ltd v Wills (1992) 177 CLR 1 at 58-59 per Brennan J; Cunliffe v The Commonwealth (1994) 182 CLR 272 at 333 per Brennan J, 384 per Toohey J; Kirk, "Section 92 in its Second Century", in Griffiths and Stellios (eds), Current Issues in Australian Constitutional Law: Tributes to Professor Leslie Zines (2020) 253 at 279-280.

    Burdens on interstate movement as reasonably necessary?

49. In some judgments concerning the intercourse limb it has been suggested that the measure taken by the law should be no more than is "reasonably required" to achieve the object of the law[48]. In another case it was said that a law should be "reasonably necessary" to a legitimate purpose[49] or "necessary or appropriate and adapted"[50] to that. The former test would seem to be more readily capable of justification; however, it is not necessary to discuss the differences between the tests or state a preference. These cases predate the acceptance by this Court in Betfair No 1[51] of a test of reasonable necessity as explaining or justifying a burden on the freedom of interstate trade and commerce. Since a law which discriminates against interstate movement will prima facie be invalid because it burdens the freedom, logically it should be capable of being justified in the same way. There is good reason in principle why the tests for justification of both limbs should be the same.

    [48]AMS v AIF (1999) 199 CLR 160 at 179 [45] per Gleeson CJ, McHugh and Gummow JJ, 232-233 [221] per Hayne J; APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322 at 353 [38] per Gleeson CJ and Heydon J, 393-394 [177], [179] per Gummow J.

    [49]Cunliffe v The Commonwealth (1994) 182 CLR 272 at 307-308 per Mason CJ, 396 per McHugh J.

    [50]Cunliffe v The Commonwealth (1994) 182 CLR 272 at 346 per Deane J.

    [51]At [37] above.

50. It should therefore be accepted that a law which is directed to discriminating against, or in fact discriminates against, interstate movement is invalid as contrary to s 92 unless it is justified by reference to a non-discriminatory purpose. It may be justified if it goes no further than is reasonably necessary to achieve a legitimate object, as this Court held in Betfair No 1.

51. It is important to bear in mind what this test requires. The approaches taken by this Court in Cole v Whitfield and Betfair No 1 are instructive. The test of reasonable necessity is not a conclusion to be stated after an impression is gained about a law's purpose and how that purpose is sought to be achieved. It requires more than a view that there exists a need to which it is the statute's purpose to respond and the measures taken are reasonable. The test is to be applied in a concrete way to determine whether the measures which the law permits are themselves reasonably necessary. It is obviously logically relevant to, if not demanded by, that enquiry whether there may be alternative, effective measures available to achieve the same object but which have less restrictive effects on the freedom. If there are, the law in question cannot be said to be reasonably necessary. This is what those cases teach[52].

    [52]Cole v Whitfield (1988) 165 CLR 360 at 408-410; Betfair No 1 (2008) 234 CLR 418 at 479-480 [110]-[112] per Gleeson CJ, Gummow, Kirby, Hayne, Crennan and Kiefel JJ; see also NationwideNews Pty Ltd v Wills (1992) 177 CLR 1 at 51 per Brennan J.

52. In some cases which preceded Betfair No 1, and which concerned both the intercourse limb and the implied freedom of political communication, it was said that a legislative measure which incidentally burdens a freedom (which is to say has that unintended, collateral effect) needs to be "appropriate and adapted"[53], "neither inappropriate nor disproportionate", "proportionate"[54] or reasonably proportionate[55] for the law to be valid. It may be said that at the least Betfair No 1 recognised the connection between the test of reasonable necessity and the concept of proportionality. It is possible to go further. The content given to the test in its application in that case, namely that there was a practicable alternative, clearly aligns it with the second test in structured proportionality, as discussed in McCloy v New South Wales[56].

    [53]Nationwide News Pty Ltd v Wills (1992) 177 CLR 1 at 57 per Brennan J; Cunliffe v The Commonwealth (1994) 182 CLR 272 at 346 per Deane J.

    [54]Australian Capital Television Pty Ltd v The Commonwealth (1992) 177 CLR 106 at 195 per Dawson J; Cunliffe v The Commonwealth (1994) 182 CLR 272 at 307-308 per Mason CJ, 366 per Dawson J, 396 per McHugh J.

    [55]Australian Capital Television Pty Ltd v The Commonwealth (1992) 177 CLR 106 at 195 per Dawson J.

    [56](2015) 257 CLR 178 at 210 [57], 216 [76] per French CJ, Kiefel, Bell and Keane JJ.

53. The origins of structured proportionality are well known, as is its acceptance by many courts, including common law courts, around the world. It has been the subject of much academic discussion. Sir Anthony Mason[57] has described structured proportionality as a "very good illustration" of one of the advantages of comparative law, namely that one "can learn from how other people go about things". The test of structured proportionality, he observed, had been advocated in Canada in R v Oakes[58], and applied in the United Kingdom in Bank Mellat v Her Majesty's Treasury [No 2][59], in New Zealand in R v Hansen[60] and in Australia in McCloy. He said:

    "The structured proportionality approach is something that courts have learnt, not only from Oakes but from Professor Barak in his book on proportionality[61]. It is a prime example of how you can learn from others."

    [57]Winkelmann et al, "Panel Discussion: Judging", in Mount and Harris (eds), The Promise of Law: Essays Marking the Retirement of Dame Sian Elias as Chief Justice of New Zealand (2020) 471 at 478.

    [58][1986] 1 SCR 103.

    [59][2014] AC 700.

    [60][2007] 3 NZLR 1.

    [61]Barak, Proportionality: Constitutional Rights and their Limitations (2012).

54. Whilst structured proportionality has its origins elsewhere, it is capable of being applied and must be applied in a particular constitutional context. Its adaptability in part accounts for its adoption globally. And as has been observed[62], the joint reasons in McCloy sought to explain structured proportionality as an "indigenous progression of the law rather than an example of explicit 'borrowing' from other jurisdictions".

    [62]Chordia, Proportionality in Australian Constitutional Law (2020) at 164.

55. It is not difficult to discern why courts have favoured its application. It reflects a rational approach to the question of whether a law which burdens a right or freedom can be justified, which requires the courts to make something of a value judgment. It discourages conclusory statements, which are apt to disguise the motivation for them, and instead exposes a court's reasoning. It is not obvious that the fact the same questions are to be applied in each case, albeit to different statutory contexts, is a bad thing. It might be said that it reflects the certainty to which the law aspires.

56. It has not been suggested in any case since McCloy that a line of argument otherwise available as a means of justifying a law has been foreclosed. No one could doubt that proportionality is necessary to justification. This Court has repeatedly said so. It cannot be suggested that structured proportionality is a perfect method. None is, but some method is necessary if lawyers and legislators are to know how the question of justification is to be approached in a given case. Structured proportionality certainly seems preferable to its main competitors. It has been said[63] that calibrated scrutiny will ultimately end up as a rules-based approach, even though it seeks to avoid that outcome, and that the problem with tiered scrutiny is that the court's task becomes one merely of categorising the case.

    [63]Sir Anthony Mason, "Foreword", in Chordia, Proportionality in Australian Constitutional Law (2020) v at vi, summarising Chordia, Proportionality in Australian Constitutional Law (2020), ch 5.

57. Long before McCloy it had been suggested by Jeremy Kirk that the stages of structured proportionality are discernible in judgments regarding s 92, albeit not expressly acknowledged by the Court as such[64]. The author gives as an example the judgment of Stephen and Mason JJ in Uebergang v Australian Wheat Board[65]. Their Honours said that validity could depend on whether there were alternative, practicable means of achieving the legitimate end with less effect on interstate trade. Their Honours also said that the test to be applied is that the legislation be "no more restrictive than is reasonable in all the circumstances, due regard being had to the public interest", which is to say balancing with the "need which is felt for regulation". This reasoning, Kirk considers, includes strict proportionality and is directed to assessing the justification of an impugned law's infringement of the s 92 freedom.

    [64]Kirk, "Constitutional Guarantees, Characterisation and the Concept of Proportionality" (1997) 21 Melbourne University Law Review 1 at 13-16, referred to in Chordia, Proportionality in Australian Constitutional Law (2020) at 147.

    [65](1980) 145 CLR 266 at 304-306.

58. There may not be universal acceptance of the application of the three tests of structured proportionality to s 92, although it is difficult to comprehend what criticism could be levelled at a requirement that a law be suitable to its non‑discriminatory purpose. This is a question which is invariably addressed in the process of construing the statute in question. One view which has been expressed[66] is that the rule stated in Cole v Whitfield with respect to the trade and commerce limb leaves no room for questions of balancing. On the other hand, notions of balancing have been said by Professor Leslie Zines[67] to be evident in Castlemaine Tooheys, which was decided after Cole v Whitfield. An acceptance of the tests of structured proportionality does not affect what was said in Cole v Whitfield. It simply explicates the tests for justification, as Betfair No 1 did.

    [66]Chordia, Proportionality in Australian Constitutional Law (2020) at 151; see also at 143, referred to in Sir Anthony Mason, "Foreword", in Chordia, Proportionality in Australian Constitutional Law (2020) v at vi.

    [67]Zines, The High Court and the Constitution, 5th ed (2008) at 59.

59. Once it is accepted that Betfair No 1, in its application to all the freedoms protected by s 92, requires that a discriminatory law must be justified as reasonably necessary, in the sense that it is understood in proportionality analysis, there seems no reason why it should not be justified as adequate in its balance. It may be shown that there is no real alternative to the law, but in some cases the burden on a freedom will be very great and the measures permitted by the law of evidently little importance, which is to say the burden is out of proportion to the need for it. Why should the burden not be said to be unjustified? Castlemaine Tooheys was a case of this kind. Proportionality in the strict sense has been considered to be appropriate by a majority of this Court in implied freedom cases[68]. It is a justification which the defendants sought to make out in this case. It should be understood to reflect the proper role of this Court as the guardian of constitutionally protected freedoms.

    [68]McCloy v New South Wales (2015) 257 CLR 178 at 218-220 [84]-[89] per French CJ, Kiefel, Bell and Keane JJ; Clubb v Edwards (2019) 267 CLR 171 at 208-209 [96]-[102] per Kiefel CJ, Bell and Keane JJ, 266-269 [270]-[275] per Nettle J, 341-345 [491]-[501] per Edelman J; Comcare v Banerji (2019) 93 ALJR 900 at 914-915 [38]-[42] per Kiefel CJ, Bell, Keane and Nettle JJ, 944-945 [202]-[206] per Edelman J; 372 ALR 42 at 57-59, 98-99.

60. This method of justification of a law may assume special importance where the law has a powerful public, protective purpose. The example given by the Commonwealth in McCloy[69], when it sought to invoke this justification, was the object of protecting security of the nation at a time of war. Similar metaphors have been applied in public discussion about the crisis affecting the health of persons during the COVID‑19 pandemic.

    [69](2015) 257 CLR 178 at 218 [84].

61. The plaintiffs, the defendants and at least three of the intervenors accepted that proportionality analysis which includes an analysis of this kind is appropriate to be utilised in considering whether a burden on s 92 is justified. No relevant distinction can be drawn as between the implied freedom of political communication and the s 92 freedoms in this regard. Each are the subject of a constitutional guarantee which has been held not to be absolute. If a burden is effected on a freedom it may be justified by any rational means. The balancing exercise is one such means and it is likely to assume special importance where statutory measures have a purpose as important as the protection of health and life.

    Section 92 precludes

62. Section 92 may be understood to preclude a law which burdens any of the freedoms there stated, as subjects of constitutional protection, where the law discriminates against interstate trade, commerce or intercourse and the burden cannot be justified as proportionate to the non‑discriminatory, legitimate purpose of the law which is sought to be achieved. Whether it is proportionate is to be determined by the tests of structured proportionality as explained by this Court.

    A constitutional limitation

63. Victoria, intervening, submitted that the principal question reserved for this Court can and should be answered by reference to the authorising provisions of the EM Act rather than by reference to any particular exercise of those statutory powers, namely the Directions. The defendants adopted these submissions. The submissions should be accepted. They accord with what was said by this Court in Wotton v Queensland[70].

    [70](2012) 246 CLR 1.

64. In Wotton, the Corrective Services Act 2006 (Qld) conferred a discretion to attach such conditions to a parole order as a parole board reasonably considered necessary to ensure the prisoner's good conduct or to prevent the prisoner committing an offence. The discretionary power, in its application to prisoners on parole, could effect a burden on the implied freedom of political communication and the conditions which were attached to the plaintiff's parole order did just that. Although argument was directed to the validity of those conditions, the question of the constitutional limitation effected by the implied freedom was determined by reference to the statute.

65. Drawing upon what Brennan J said in Miller v TCN Channel Nine Pty Ltd[71], the joint judgment in Wotton[72] explained that the exercise of the statutory power to condition the parole order might be subject to judicial review under the Judicial Review Act 1991 (Qld), but the question of compliance with the constitutional limitation is answered by the construction of the statute. This is consistent with an understanding that constitutionally guaranteed freedoms operate as limits on legislative and executive power. Their Honours accepted that[73]:

    "if, on its proper construction, the statute complies with the constitutional limitation, without any need to read it down to save its validity, any complaint respecting the exercise of power thereunder in a given case, such as that in this litigation concerning the conditions attached to the Parole Order, does not raise a constitutional question, as distinct from a question of the exercise of statutory power".

    [71](1986) 161 CLR 556 at 613‑614.

    [72](2012) 246 CLR 1 at 9-10 [10], 13-14 [21], [24] per French CJ, Gummow, Hayne, Crennan and Bell JJ; see also at 29-30 [74] per Kiefel J.

    [73]Wotton v Queensland (2012) 246 CLR 1 at 14 [22].

66. The provisions of the Corrective Services Act were held to comply with the constitutional limitation on State legislative power because they were reasonably necessary or reasonably appropriate and adapted to a legitimate purpose, as Lange v Australian Broadcasting Corporation[74] requires, which is to say they were proportionate[75].

    [74](1997) 189 CLR 520.

    [75]Wotton v Queensland (2012) 246 CLR 1 at 16 [31]-[33] per French CJ, Gummow, Hayne, Crennan and Bell JJ; see also at 33-34 [89]-[92] per Kiefel J.

67. The clarification of where the constitutional question involving freedoms resides is admittedly recent. The delay in stating it may in part be explained by difficulties which attended administrative law and its remedies[76] for some time and which have only been resolved relatively recently. In any event the approach taken in Wotton is that which should now be followed.

    [76]Stellios, "Marbury v Madison: Constitutional Limitations and Statutory Discretions" (2016) 42 Australian Bar Review 324 at 327-328.

68. In some cases difficult questions may arise because the power or discretion given by the statute is broad and general. No such question arises in this matter. As will be seen, the power to prohibit or restrict entry into a declared emergency area, which may be the whole of Western Australia, is largely controlled by the EM Act itself and is proportionate to its purposes.

    Discrimination, burden and justification

69. The power provided by s 56(1) of the EM Act to make an emergency declaration is controlled by s 56(2), which requires that there be an "emergency" or that one is imminent and that extraordinary measures are necessary to protect the life and health of persons. The definitions of "emergency" and "hazard" identify an epidemic as subject to such measures.

70. When an emergency declaration is made it remains in effect for only a short period. Its extension for a longer period requires a further declaration by the Minister. Whilst a state of emergency exists action for the purpose of management of the emergency may be taken, including for the prevention of the occurrence of a plague or an epidemic. By s 67, the prohibition of the movement of persons into a declared emergency area is such an action.

71. The plaintiffs submitted that the Directions are directed to preventing interstate movement. Conformably with an approach which has regard to the provisions of the EM Act, the plaintiffs may be understood to submit that those provisions in their application to prevent the entry of persons into Western Australia may be seen as directed to preventing interstate movement. The text of these provisions does not provide support for that submission. They are not directed to the Western Australian border and movement across it. They apply to an emergency area the subject of an emergency declaration, which may be the whole or part of the State, and they may apply to all persons outside the emergency area who seek to enter the area, whether from other States or Territories or from overseas.

72. It cannot therefore be said that by their terms ss 56(1) and 67 of the EM Act discriminate against interstate movement. It must be accepted that in its application to a person coming to the border of Western Australia from the other States and Territories and seeking entry, s 67 will hinder interstate movement and, to that extent, discriminate against it. For the discrimination to occur in this connection it is not necessary that s 67 be seen to favour intrastate movement, as explained earlier in these reasons. But to the extent that s 67 discriminates against interstate movement by preventing it, the provision effects a burden on the freedom.

73. The plaintiffs contended that the decision of this Court in Gratwick v Johnson[77] applies to this case. They did not seek to rely upon the aspect of that decision which gave effect to a personal right to pass freely between the States. The plaintiffs did not contend for such a right in connection with the intercourse limb of s 92. They may be understood to submit that the EM Act provisions are not materially different from the regulations which were held to be invalid in Gratwick.

    [77](1945) 70 CLR 1.

74. The submission cannot be accepted. The regulations in Gratwick provided that no person should travel by rail or vehicle between the States without a permit. They were held to be directed against and a direct interference with freedom of intercourse among the States[78]. The regulations in Gratwick may readily be distinguished from the provisions of the EM Act, which have a purpose other than to restrict unauthorised movement. The restrictions they authorise are directed to the protection of the health of residents of Western Australia.

    [78]Gratwick v Johnson (1945) 70 CLR 1 at 14 per Latham CJ, 16 per Rich J, 17 per Starke J, 19-20 per Dixon J, 22 per McTiernan J.

75. It was not necessary for the Court in Gratwick to consider whether the law was necessary for a purpose other than to prevent interstate movement since none was suggested. Earlier authority had held that a State law which restricted interstate movement for other, legitimate reasons might be valid. In R v Smithers; Ex parte Benson[79], Barton J, in describing the scope of the freedom assured to citizens by s 92, said that he should not be thought to say that it destroyed the right of States to take "any precautionary measure in respect of the intrusion from outside the State of persons who are or may be dangerous to its domestic order, its health, or its morals". And in Ex parte Nelson [No 1][80], which concerned prohibitions on the introduction of infected or contagious livestock into a State, it was said that whilst the establishment of freedom of trade between the States is a most notable achievement of the Constitution, it would be a strange result if that achievement had the effect of stripping the States of the power to protect their citizens from the dangers of infectious diseases, however those dangers might arise. Mason J's view of the measures in the North Eastern Dairy Co[81] case may be seen to proceed from a similar viewpoint, although his Honour concluded they went further than was necessary for the purpose of protecting the public from contaminated milk.

    [79](1912) 16 CLR 99 at 110.

    [80](1928) 42 CLR 209 at 218 per Knox CJ, Gavan Duffy and Starke JJ.

    [81](1975) 134 CLR 559 at 607-608, 616.

76. The plaintiffs accepted that if the purpose of the restrictions is held to be to prevent infectious diseases such as COVID-19 spreading into the Western Australian community, the question becomes one of justification. They then argued that it cannot be shown that the power to restrict the entry of persons into Western Australia is suitable or necessary to that purpose. The power to restrict should be capable of being adapted or lessened to accommodate the different levels of risk which persons seeking entry into the State might present.

77. There can be no doubt that a law restricting the movement of persons into a State is suitable for the purpose of preventing persons infected with COVID-19 from bringing the disease into the community. Further, the matters necessary to be considered before such restrictions can be put in place, including with respect to an emergency declaration and the shortness of the period of an emergency declaration, suggest that these measures are a considered, proportionate response to an emergency such as an epidemic.

78. The plaintiffs may be understood to contend that there is an alternative to a power of prohibition on persons from outside Western Australia entering the State. Entry could be allowed to persons from States where the disease is largely under control and who present a low risk of bringing it into the community. The underlying premise of this argument is that there is a level of risk which may be regarded as acceptable. This misapprehends Rangiah J's findings.

79. His Honour did not suggest that a low risk of an infected person entering Western Australia was acceptable from a public health perspective. His Honour considered that once a person infected with COVID-19 enters the community there is a real risk of community transmission and that it may become uncontrollable. Because of the uncertainties about the level of risk and the severe, or even catastrophic, outcomes which might result from community transmission, a precautionary approach should be adopted.

80. These findings leave little room for debate about effective alternatives. They provide no warrant for reading the power to prohibit entry into Western Australia during a pandemic down to accommodate some undefined level of risk. Accepting that s 67 must accommodate a requirement that it be exercised proportionately, the defendants' submission that there is no effective alternative to a general restriction on entry must be accepted.

81. The defendants also submitted that once it is accepted that the purpose of the EM Act provisions is a legitimate, non‑discriminatory purpose of protecting the public health of residents of Western Australia and that there are no other reasonable means available to achieve that purpose, it follows that they have established that the laws are adequate in the balance. This somewhat misstates the latter justification, proportionality in the strict sense. It requires that the importance of the public health purpose be measured against the extent of the restriction on the freedom. It must be accepted that the restrictions are severe but it cannot be denied that the importance of the protection of health and life amply justifies the severity of the measures.

82. The same conclusions apply to the plaintiffs' case respecting interstate trade and commerce. The plaintiffs did not provide extensive written submissions on this alternative aspect of their case and did not further elaborate on them in oral argument. They did not rely upon evidence as to economic effects such as might be weighed against effects on health, assuming that is possible. The only additional matter that they raised respecting the laws so far as concerns interstate trade is that they have a protectionist purpose in the sense applicable to trade. That is clearly incorrect.

83. GAGELER J. Section 92 of the Constitution emphatically and imperatively declares that "trade, commerce, and intercourse among the States ... shall be absolutely free". The "riddle of s 92" lies in the question begged by the constitutional text: "absolutely free from what?"[82]

    [82]Wilcox Mofflin Ltd v New South Wales (1952) 85 CLR 488 at 539.

84. Cutting through the debris left by some 140 earlier failed judicial attempts to resolve that riddle, Cole v Whitfield[83] provided a partial resolution. The partial resolution proceeded on the understanding that "[t]he notions of absolutely free trade and commerce and absolutely free intercourse are quite distinct and neither the history of [s 92] nor the ordinary meaning of its words require that the content of the guarantee of freedom of trade and commerce be seen as governing or governed by the content of the guarantee of freedom of intercourse"[84].

    [83](1988) 165 CLR 360.

    [84](1988) 165 CLR 360 at 388.

85. Cole v Whitfield authoritatively determined that trade and commerce among the States is guaranteed by s 92 to be absolutely free from "discriminatory burdens of a protectionist kind"[85]. The guarantee of the trade and commerce limb is of absolute freedom from laws imposing differential burdens on interstate trade or commerce (in comparison to intrastate trade or commerce) which cannot be justified as a constitutionally permissible means of pursuing constitutionally permissible non-discriminatory legislative ends and which operate to the competitive advantage of intrastate trade or commerce. Subsequent cases on the trade and commerce limb of the guarantee[86] eventually settled on the standard to be met for a differential burden on interstate trade or commerce to be justified as a constitutionally permissible means of pursuing a non-discriminatory legislative end. The standard, authoritatively determined in Betfair Pty Ltd v Western Australia ("Betfair [No 1]"), is that of "reasonable necessity"[87].

    [85](1988) 165 CLR 360 at 394, 398. See also at 407-408.

    [86]Bath v Alston Holdings Pty Ltd (1988) 165 CLR 411; Street v Queensland Bar Association (1989) 168 CLR 461; Castlemaine Tooheys Ltd v South Australia (1990) 169 CLR 436; Barley Marketing Board(NSW)v Norman (1990) 171 CLR 182; APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322; Betfair Pty Ltd v Western Australia (2008) 234 CLR 418 ("Betfair [No 1]"); Betfair Pty Ltd v Racing New South Wales (2012) 249 CLR 217 ("Betfair [No 2]"); Sportsbet Pty Ltd v New South Wales (2012) 249 CLR 298.

    [87](2008) 234 CLR 418 at 477 [102]-[103]. See also Betfair [No 2] (2012) 249 CLR 217 at 269 [52].

86. What intercourse among the States is guaranteed by s 92 to be absolutely free from, Cole v Whitfield left to be resolved on another day. Left also for another day was the associated question of how the "intercourse limb" relates to the "trade and commerce limb" in respect of intercourse that occurs in trade or commerce. Subsequent cases touching on the intercourse limb[88] have yielded no definitive answer.

    [88]Australian Capital Television Pty Ltd v The Commonwealth (1992) 177 CLR 106; Nationwide News Pty Ltd v Wills (1992) 177 CLR 1; Cunliffe v The Commonwealth (1994) 182 CLR 272; AMS v AIF (1999) 199 CLR 160; APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322.

87. The occasion for resolution of that part of the riddle of s 92 left unresolved by Cole v Whitfield arose in the midst of a pandemic in the context of determining a proceeding brought by a resident of Queensland against the State of Western Australia, in the original jurisdiction conferred on the High Court by s 75(iv) and under s 76(i) of the Constitution, challenging directions contained in the Quarantine (Closing the Border) Directions (WA) ("the Directions") made under the Emergency Management Act 2005 (WA) ("the Act").

88. The Act, to the detail of which I will in due course turn, relevantly empowers the Western Australian Minister for Emergency Services to make and periodically renew a declaration that a state of emergency exists in an "emergency area", comprising the whole or any area or areas of Western Australia, in respect of the occurrence of a plague or epidemic of a nature that requires a significant and coordinated response[89]. For so long as a state of emergency declaration is in force, the Act empowers an authorised officer to give a general direction prohibiting movement of persons into or out of the declared emergency area for the purpose of combating the effects of the declared emergency[90].

    [89]Section 56 of the Act, read with the definitions of "emergency", "emergency area" and "hazard" in s 3 of the Act.

    [90]Section 67 of the Act, read with the definition of "emergency management" in s 3 of the Act.

89. On 15 March 2020, the Minister for Emergency Services made, and afterwards periodically renewed, a declaration that a state of emergency existed in the whole of Western Australia in respect of "the pandemic caused by COVID-19". For the express purpose of "limit[ing] the spread of COVID-19"[91], the State Emergency Coordinator soon afterwards made, and then periodically revised, the Directions. The impugned directions were expressed to prohibit entry of persons into Western Australia[92].

    [91]Paragraph 1 of the Directions.

    [92]Paragraphs 4 and 5 of the Directions.

90. On 6 November 2020, I joined in answering questions reserved in the proceeding for the consideration of the Full Court. The answer to the sole substantive question in which I then joined was to the effect that the provisions of the Act which authorised the making of directions of the kind impugned comply with both limbs of s 92 in all their potential applications. The consequence was that the validity of the impugned directions raised no constitutional question. The plaintiffs had disavowed any argument that the impugned directions were not authorised by the Act. The challenge to the impugned directions therefore failed.

91. Now giving reasons for the decision I then reached, I proceed immediately to explain my reasoning on the substantive issues. The structure of my reasoning is as follows.

92. At the outset, I deal with the resolution of that part of the riddle of s 92 left unresolved by Cole v Whitfield. I address what it means for intercourse among the States to be absolutely free: it means interstate intercourse must be absolutely free from discriminatory burdens of any kind. The guarantee of the intercourse limb is of absolute freedom from laws imposing differential burdens on interstate intercourse (in comparison to intrastate intercourse) which cannot be justified as a constitutionally permissible means of pursuing constitutionally permissible non-discriminatory legislative ends. I explain as well that the guarantees of absolute freedom of trade and commerce and absolute freedom of intercourse each apply to intercourse that occurs in trade or commerce.

93. Next, I explain why compliance with the guarantees of absolute freedom of trade and commerce and absolute freedom of intercourse was appropriately determined by considering whether the provisions of the Act which authorise the making of directions of the kind impugned met the standard of reasonable necessity required to comply with both limbs of s 92 in all their potential applications, rather than by considering whether the impugned directions directly complied with that standard.

94. Next, I turn to "structured proportionality". In short, I reject it. My view is that the standard to be met for a differential burden on interstate trade or commerce or on interstate intercourse to be justified as a constitutionally permissible means of pursuing a constitutionally permissible non-discriminatory legislative end should remain the standard of reasonable necessity authoritatively determined in Betfair [No 1]. 

95. Finally, having established the parameters of what I consider to be the appropriate analysis, I explain quite briefly how the relevant provisions of the Act meet the requisite standard of constitutional justification.

    Interstate intercourse: absolutely free from what?

96. The resolution of that part of the riddle of s 92 left unresolved by Cole v Whitfield was provided by Jeremy Kirk SC in an essay published on the eve of the onset of the pandemic[93]. The argument presented in the essay was an elaboration of an argument put by the Attorney-General of the Commonwealth intervening in Cole v Whitfield[94]. The argument was adopted by the Attorney-General of Queensland intervening in the present proceeding, and was ultimately accepted by the plaintiffs in reply. I am persuaded that the argument is sound.

    [93]Kirk, "Section 92 in its Second Century", in Griffiths and Stellios (eds), Current Issues in Australian Constitutional Law: Tributes to Professor Leslie Zines (2020) 253.

    [94](1988) 165 CLR 360 at 368.

97. The argument, which I accept, is to the effect that intercourse among the States is guaranteed by s 92 to be absolutely free from all discriminatory burdens. The guarantee of the intercourse limb is of absolute freedom from laws imposing differential burdens on interstate intercourse (in comparison to intrastate intercourse) which cannot be justified as a constitutionally permissible means of pursuing non-discriminatory legislative ends. The standard to be met for a differential burden on interstate intercourse to be justified as a constitutionally permissible means of pursuing a non-discriminatory legislative end, no differently from the standard to be met for a differential burden on interstate trade or commerce to be justified as a constitutionally permissible means of pursuing a non-discriminatory legislative end, is the standard of reasonable necessity.

98. Understood in that way, the guarantee of absolute freedom of interstate intercourse mirrors the guarantee of absolute freedom of interstate trade and commerce to the extent that: each invokes the same essential notion of discrimination as lying in "the unequal treatment of equals, and, conversely, in the equal treatment of unequals"[95]; each posits the same essential comparison between that which is interstate and that which is intrastate; each demands "an acceptable explanation or justification for [any] differential treatment"[96]; and each imposes, as the measure of justification for differential treatment, satisfaction of the same standard of reasonable necessity.

    [95]Castlemaine Tooheys Ltd v South Australia (1990) 169 CLR 436 at 480.

    [96]Castlemaine Tooheys Ltd v South Australia (1990) 169 CLR 436 at 477; Betfair[No 1] (2008) 234 CLR 418 at 478-480 [106]-[113].

99. The guarantee of absolute freedom of interstate intercourse differs from the guarantee of absolute freedom of interstate trade and commerce only to the extent that absolute freedom of interstate intercourse extends to freedom from discriminatory burdens of any kind. That is to say, the guarantee of absolute freedom of interstate intercourse is infringed by any differential burden on interstate intercourse that cannot be justified. An unjustified differential burden on interstate intercourse need not operate to the competitive advantage of intrastate trade or commerce.

100. That understanding of the intercourse limb fits comfortably with the imputed constitutional purpose of s 92 indicated by the pre‑federation history expounded in Cole v Whitfield[97] and elaborated in Betfair [No 1][98]. The purpose was "to create a free trade area throughout the Commonwealth and to deny to Commonwealth and States alike a power to prevent or obstruct the free movement of people, goods and communications across State boundaries"[99].   

     [97](1988) 165 CLR 360 at 385-391.

     [98](2008) 234 CLR 418 at 454-459 [21]-[32].

     [99](1988) 165 CLR 360 at 391.

101. The constitutional purpose derives from a structural imperative. Betfair [No 1] drew attention to the "apparent, albeit at times inconvenient, truth" that democratically elected legislatures in a political subdivision of a federal system have a structural incentive to "protect and promote the interests of their own constituents"[100]. The Constitution of the Commonwealth of Australia, like that of the United States, "was framed under the dominion of a political philosophy less parochial in range"[101].

     [100](2008) 234 CLR 418 at 459-460 [34]-[35], quoting Tribe, American Constitutional Law, 3rd ed (2000), vol 1 at 1051-1052.

     [101]Betfair [No 1] (2008) 234 CLR 418 at 460 [35], quoting Baldwin v G A F Seelig Inc (1935) 294 US 511 at 523.

102. By 1891, when the First National Australasian Convention, on the motion of Sir Henry Parkes, resolved principles "to establish and secure an enduring foundation for the structure of a federal government"[102], the inconvenient truth of democratically elected legislatures in political subdivisions of a federal system having a structural incentive to protect and promote the interests of their own constituents had been demonstrated through long experience in the United States. There, forces of localism had repeatedly been experienced to result in State laws protecting in-State traders and producers against out-of-State traders and producers. The Supreme Court had repeatedly held State laws of that protectionist character to be within the purview of the freedom of trade guaranteed by the "dormant" operation of the "commerce clause"[103], relevantly expressed to confer power on the United States Congress "[t]o regulate Commerce with foreign Nations, and among the several States"[104]. But much the same forces of localism had also been experienced to result in State laws prohibiting entry into a State by non-State citizens within categories considered to be undesirable[105], taxing entry into a State by non-State citizens[106], taxing citizens seeking to leave a State and taxing non-State citizens seeking simply to pass through a State[107]. Countering those forces in a non-commercial context, the Supreme Court had declared in 1867 that, independently of the dormant operation of the commerce clause, all citizens of the United States, "as members of the same community, must have the right to pass and repass through every part of it without interruption, as freely as in [their] own States"[108].

     [102]Official Report of the National Australasian Convention Debates (Sydney), 4 March 1891 at 23.

     [103]Notably, Guy v Baltimore (1879) 100 US 434 and Minnesota v Barber (1890) 136 US 313, discussed in Betfair [No 1] (2008) 234 CLR 418 at 462-464 [42]-[47].

     [104]United States Constitution, Art I, §8, cl 3.

     [105]New York v Miln (1837) 36 US 102.

     [106]The Passenger Cases (1849) 48 US 283.

     [107]Crandall v Nevada (1867) 73 US 35.

     [108]Crandall v Nevada (1867) 73 US 35 at 49, quoting The Passenger Cases (1849) 48 US 283 at 492. See Willoughby, The Constitutional Law of the United States, 2nd ed (1929) at 1076.

103. Of the principles proposed by Sir Henry Parkes, and that were later adopted by the First National Australasian Convention, the first was "[t]hat the powers and privileges and territorial rights of the several existing colonies shall remain intact, except in respect to such surrenders as may be agreed upon as necessary and incidental to the power and authority of the National Federal Government". The second, which necessarily qualified the first and which came to be embodied in s 92, was "[t]hat the trade and intercourse between the federated colonies ... shall be absolutely free"[109].  

     [109]Official Report of the National Australasian Convention Debates (Sydney), 4 March 1891 at 23.

104. Speaking to the second of those principles, and of its centrality to the Australian federal project, Sir Henry Parkes said[110]:

     "By my next condition I seek to define what seems to me an absolutely necessary condition of anything like perfect federation, that is, that Australia, as Australia, shall be free - free on the borders, free everywhere - in its trade and intercourse between its own people; that there shall be no impediment of any kind - that there shall be no barrier of any kind between one section of the Australian people and another; but, that the trade and the general communication of these people shall flow on from one end of the continent to the other, with no one to stay its progress or to call it to account; in other words, if this is carried, it must necessarily take with it the shifting of the power of legislation on all fiscal questions from the local or provincial parliaments to the great national Parliament sought to be created. To my mind, it would be futile to talk of union if we keep up these causes of disunion. It is, indeed, quite apparent that time, and thought, and philosophy, and the knowledge of what other nations have done, have settled this question in that great country to which we must constantly look, the United States of America."

     As noted by Professor La Nauze[111], the second principle was agreed to without discussion and "'absolutely free' was, to coin a phrase, absolutely free of legal criticism in open Convention".

     [110]Official Report of the National Australasian Convention Debates (Sydney), 4 March 1891 at 24.

     [111]La Nauze, "A Little Bit of Lawyers' Language: The History of 'Absolutely Free', 1890-1900", in Martin (ed), Essays in Australian Federation (1969) 57 at 70-71.

105. Understanding the intercourse limb of s 92 as a guarantee of absolute freedom from discriminatory burdens also fits well with Cole v Whitfield's reference to the intercourse limb extending to "a guarantee of personal freedom"[112], the content of which was indicated by Gratwick v Johnson, where the operation of s 92 was described as protecting against legislation "pointed directly at the passing of people to and fro among the States"[113]. That reference to personal freedom was plainly to freedom of movement of persons and cannot be taken to suggest the conferral of an individual right. The language used in Gratwick to describe the freedom was drawn from James v The Commonwealth[114] which, as Cole v Whitfield went on to observe, employed a "notion of freedom as at the frontier" on one view little different from "the notion of freedom from burdens of a discriminatory kind"[115].

     [112](1988) 165 CLR 360 at 393.

     [113](1945) 70 CLR 1 at 17. See also at 14.

     [114](1936) 55 CLR 1; [1936] AC 578.

     [115](1988) 165 CLR 360 at 397.

106. Gratwick usefully illustrates a differential burden on interstate intercourse which was not justified as a constitutionally permissible means of pursuing a constitutionally permissible non-discriminatory legislative end. Found wanting in that case was a statutory order purporting to prohibit interstate, but not intrastate, travel by rail or commercial passenger vehicle during a time of war. As put by Dixon J, the prohibition imposed by the statutory order was "simply based on the 'inter-Stateness' of the journeys it assume[d] to control"[116]. Although the statutory order was purportedly made pursuant to a statutory regime confining orders restricting movement to those in the interests of defence of the Commonwealth and effectual prosecution of the war, his Honour observed that it was "going a long way to suggest that the imperative demands of national safety necessitate a general prohibition operating in every part of the continent of travelling without a permit by public conveyance, but only if it is a journey with its terminus a quo in one State and its terminus ad quem in another State"[117].

     [116](1945) 70 CLR 1 at 19.

     [117](1945) 70 CLR 1 at 20.

257. Secondly, the only discrimination that was alleged in Cole v Whitfield was discrimination in a protectionist sense. Underlying the reasoning that the test for the trade and commerce aspect must be limited only to protectionist discrimination may have been a formal fallacy based on the fact that most observed instances of discrimination, and most of the discussion at the Convention Debates, involved protectionism. This formal fallacy may also have been the reason that this Court said in Cole v Whitfield that the pre‑1900 United States cases on the negative commerce clause were not of "any assistance" in the interpretation of s 92[409], a view that has since been quietly jettisoned[410]. As I have noted above, a similar formal fallacy based upon the usual association of interstate trade with interstate intercourse has not been committed; interstate intercourse has not been limited to commercial intercourse.

     [409](1988) 165 CLR 360 at 405.

     [410]Betfair Pty Ltd v Western Australia (2008) 234 CLR 418 at 459‑464 [33]-[48]. See Gleeson, "What's left of Cole v Whitfield?" (2013) 24 Public Law Review 97 at 101.

258. Thirdly, the Court in Cole v Whitfield acknowledged that the existence of the intercourse aspect suggested a "wider operation"[411] of the trade and commerce aspect than merely guarding against discrimination in a protectionist sense. But the force of this point was thought to be diminished because the Court assumed that if the test treated the trade and commerce aspect and the intercourse aspect alike then "anarchy would result"[412]. This assumption would not have been made if the Court had accepted that freedom of intercourse was also concerned with guarding against discrimination generally between the States in relation to intercourse.

     [411](1988) 165 CLR 360 at 393.

     [412]Cole v Whitfield (1988) 165 CLR 360 at 393.

259. Fourthly, although the removal of the protectionist element from discrimination in the trade and commerce aspect involves some adjustment to the understanding of the trade and commerce aspect outlined in Cole v Whitfield, in practical effect an almost identical adjustment is required by recognising a test for discrimination, without a requirement of protectionism, for the intercourse aspect of s 92. This is because interstate trade and commerce will almost always involve intercourse. An example of a case where the same adjustment would have to be made even without removing the protectionist element from discrimination in the trade and commerce aspect is Barley Marketing Board (NSW) v Norman[413].

     [413](1990) 171 CLR 182.

260. In Barley Marketing Board, the defendants attempted to engage in interstate commercial intercourse by selling barley grown in New South Wales to a buyer in Victoria. New South Wales legislation prohibited the defendants from doing so by establishing a marketing board into which was vested title to all barley coming into existence in New South Wales. The Court observed that there was no evidence that the scheme restricted the supply of barley to other States[414] and that there was no vesting of title to imported barley[415]. Further, it appears there was no evidence before the Court that the prices at which the board sold the barley interstate were higher than those prices which New South Wales producers would have charged in interstate sales[416]. The Court therefore held that the scheme was not protectionist[417]. If the requirement of protectionism were removed the case would have to be assessed against a broader criterion of discrimination. The defendants were subject to restrictions upon selling in Victoria that did not apply to producers in Victoria. The focus in the case upon protectionism meant that it was not necessary for the Court to explore whether this discrimination in the course of commercial intercourse conferred an advantage on Victorian producers which was unjustified. But since the defendants' conduct involved commercial intercourse between the States, and thus engaged the intercourse aspect of s 92, that broader assessment of discrimination would be required anyway by complete consideration of the unitary freedom of trade, commerce, and intercourse.

     [414]Barley Marketing Board (NSW) v Norman (1990) 171 CLR 182 at 204.

     [415]Barley Marketing Board (NSW) v Norman (1990) 171 CLR 182 at 201-202, referring to North Eastern Dairy Co Ltd v Dairy Industry Authority of NSW (1975) 134 CLR 559.

     [416]Compare Gray, "Compulsory Marketing Schemes and Section 92 of the Australian Constitution" (2014) 33 University of Tasmania Law Review 317 at 331.

     [417]Barley Marketing Board (NSW) v Norman (1990) 171 CLR 182 at 204.

     Justifying discrimination by a structured proportionality analysis

261. Putting to one side the difficulties involved in limiting discrimination in the trade and commerce aspect to protectionist discrimination, the test for compliance with s 92 can be simply expressed. The constitutional guarantee that "trade, commerce, and intercourse among the States ... shall be absolutely free" imposes a requirement that laws concerning movement across a border – whether it be goods, persons, or communications or other intangibles – cannot discriminate by imposing an unjustified burden on trade, commerce, or intercourse in one State compared with another.

262. The development of a transparent and concise test of discrimination should not be undermined by a vague and opaque approach to justification. A significant step was taken in Castlemaine Tooheys Ltd v South Australia[418] towards making transparent the approach to justification of a law that burdens trade, commerce, or intercourse in the proscribed way. In that case, five members of this Court said that a law that imposes a burden upon interstate trade and commerce would be "appropriate and adapted" if it imposed a burden that was incidental and was not disproportionate to the object to be achieved.

     [418](1990) 169 CLR 436 at 473.

263. This step, while significant, did not complete the movement towards transparency. By themselves, words like "appropriate and adapted" or "disproportionate" still conceal underlying reasoning and leave open a vast area for the exercise of discretion and subjective preference. More is also needed to provide clarity (i) for the State and Commonwealth Parliaments and (ii) for the States and the Commonwealth to attempt to discharge their onus of justifying relevantly discriminatory laws. Judicial reasoning concerning constitutional validity of legislation should not be a black box to be unlocked only when parties to a later case seek explanation for the earlier exercise of discretion. As Professor Birks observed when discussing unstructured discretion[419]:

     "The whole point of the rule of law is to ensure that power which cannot be put under the law should be accountable to the electorate and that, for the rest, we all live under the law, not under the wills and whims of a person or a group of people. The blessings of this commitment have been overlooked by the discretionary remedialists, who suddenly suppose that the judges should be the one group answerable only to God."

     [419]Birks, "Three Kinds of Objection to Discretionary Remedialism" (2000) 29 University of Western Australia Law Review 1 at 15.

264. It is no surprise that a form of structured proportionality analysis has been said to have been adopted by "virtually every effective system of constitutional justice in the world, with the partial exception of the United States"[420], and even there the balancing approach may be best understood as a less structured form of proportionality[421]. In Australia, a structured proportionality analysis is now well established in the context of the implied freedom of political communication as a means to elucidate concepts such as "appropriateness". It was an analysis that was adopted by a majority of this Court in McCloy v New South Wales[422], Brown v Tasmania[423], Unions NSW v New South Wales[424], and Clubb v Edwards[425]. The need for structure and transparency is no less for an analysis of the compatibility of laws with s 92. A similar analysis should be adopted, to make explicit that which would otherwise be implicit, when assessing whether a law which places a burden on the freedom guaranteed by s 92 is justified[426].

     [420]See Clubb v Edwards (2019) 267 CLR 171 at 332 [466], quoting Stone Sweet and Mathews, "Proportionality Balancing and Global Constitutionalism" (2008) 47 Columbia Journal of Transnational Law 72 at 74 and referring to Barak, Proportionality: Constitutional Rights and their Limitations (2012) at 181-210.

     [421]Clubb v Edwards (2019) 267 CLR 171 at 331 [465].

     [422](2015) 257 CLR 178 at 193-195 [2]-[3].

     [423](2017) 261 CLR 328 at 368-369 [123]-[127], 416-417 [278].

     [424](2019) 264 CLR 595 at 615 [42], 638 [110].

     [425](2019) 267 CLR 171 at 186 [5]-[6], 264-265 [266], 330-331 [462]-[463].

     [426]See Kirk, "Constitutional Guarantees, Characterisation and the Concept of Proportionality" (1997) 21 Melbourne University Law Review 1 at 12-15; Kiefel, "Section 92: Markets, Protectionism and Proportionality – Australian and European Perspectives" (2010) 36(2) Monash University Law Review 1 at 10, 13-15; Stellios, Zines's The High Court and the Constitution, 6th ed (2015) at 57; Kirk, "Section 92 in its Second Century", in Griffiths and Stellios (eds), Current Issues in Australian Constitutional Law: Tributes to Professor Leslie Zines (2020) 253 at 259; cf Puig, The High Court of Australia and Section 92 of the Australian Constitution (2008) at 143-150; Chordia, Proportionality in Australian Constitutional Law (2020) at 147‑149.

265. Structured proportionality makes explicit and transparent the only three independent grounds upon which a law might be held invalid as contrary to s 92. First, a law will be invalid if its very purpose is to undermine the freedom guaranteed by s 92. Secondly, a law will be invalid if its means of achieving its legitimate purpose are not "reasonably necessary", in the sense that those means burden the freedom guaranteed by s 92 substantially more than obvious and compelling alternatives which could achieve the purpose of the law to the same extent. Thirdly, and in absolutely exceptional cases, a law will be invalid if its legitimate, but trivial, purpose is inadequate to support the extent of the burden placed upon the high constitutional purpose of s 92.

266. The "structure" in structured proportionality is rigid in its refusal to countenance fictions or hidden grounds for invalidating legislation. As a matter of logic, each stage of the enquiry also follows the preceding stage. The first requires the identification of a legitimate purpose. The second requires assessment of the extent to which the means of achieving that legitimate purpose, not some other – hypothetical or fictional – purpose, is necessary. The third assesses whether, despite the reasonable necessity of the means adopted to achieve the legitimate purpose, the purpose nevertheless cannot justify the burden upon the constitutional freedom.

267. One objection to this form of structured proportionality is that there is no place for the third stage of the analysis. In Betfair Pty Ltd v Western Australia[427] the third stage was not mentioned. The third stage requires a comparison of the importance of competing policies, upon which Parliament is far better suited to judge in a representative democracy. There is great force to this objection. In Clubb v Edwards[428], I explained why this third basis for invalidating laws must be highly exceptional. The third stage permits the invalidation of a law even though the purpose of the law is legitimate and despite the means adopted being reasonably necessary to achieve that purpose. In other words, invalidation at the third stage of a law that has satisfied the first two stages might have the effect that Parliament can never legislate to achieve that legitimate purpose. Ultimately, however, as I explain later in these reasons, there may be extreme examples of laws whose legitimate but trivial purpose cannot justify a necessary, but extreme, burden upon the important freedom of trade, commerce, and intercourse. 

     [427](2008) 234 CLR 418 at 464 [48], 477 [102].

     [428](2019) 267 CLR 171 at 341-344 [491]-[498].

268. Another objection involves an assertion that structured proportionality can have the effect that unspecified factors are ignored or suppressed or that too much weight is put on specified factors. On this view, it is better to allow unspecified factors to roam free, perhaps unmentioned and possibly even subconscious, in a broad evaluative judgment of invalidity. But what are these factors and how would they lead to a conclusion of invalidity? And as to the complaint about excessive weight, why should legislation be held valid if it failed any of the stages of structured proportionality analysis? For instance, is it to be suggested that legislation should be upheld despite having an illegitimate purpose or despite adopting means which burden the s 92 freedom but are not reasonably necessary to achieve its legitimate purpose?

     Proportionality stage one: the purpose of the law

269. A question which is logically anterior to any other stage of proportionality analysis is whether the law is suitable in that it has a rational connection with a legitimate purpose. In the context of justifying a law that would otherwise be contrary to s 92, the question is most neatly expressed as whether the law has an illegitimate purpose. If one of the very purposes of the legislative provision is to discriminate in the manner prohibited by s 92 then the law cannot be justified. Section 92, as a constitutional norm, could not sanction a law with the very purpose of undermining that norm.

270. The purpose of the legislative provision, in this sense, is the object, goal, or aim of the law rather than merely the effect of the law[429]. Of course, since purpose or intention can be inferred from likely effect[430], a discriminatory effect of the law that is very likely or an obvious substantial disproportion with expressed objects of the law might be bases for an inference that the discrimination was an intended purpose. But a law will only fail at this stage if one of its very purposes is to achieve that which was proscribed. Expressions such as "pointed directly at"[431], "aimed at"[432], or "directed against"[433], might be said to be "unsatisfactory" descriptions[434] because to the extent that those expressions mean something different from purpose then they should not be sufficient for establishing invalidity.

     [429]See, generally, Unions NSW v New South Wales (2019) 264 CLR 595 at 656-657 [168]-[172]. See also McCloy v New South Wales (2015) 257 CLR 178 at 205 [40]; Brown v Tasmania (2017) 261 CLR 328 at 362 [99], 392 [209], 432‑433 [322].

     [430]Zaburoni v The Queen (2016) 256 CLR 482 at 488 [8]; SZTAL v Minister for Immigration and Border Protection (2017) 262 CLR 362 at 394-397 [96]-[101].

     [431]R v Smithers; Ex parte Benson (1912) 16 CLR 99 at 118.

     [432]Nationwide News Pty Ltd v Wills (1992) 177 CLR 1 at 58.

     [433]Milk Board (NSW) v Metropolitan Cream Pty Ltd (1939) 62 CLR 116 at 127.

     [434]Compare Cole v Whitfield (1988) 165 CLR 360 at 401.

     Proportionality stage two: reasonable necessity

271. If the law has a legitimate purpose but has an effect of discriminating between States in trade, commerce, or intercourse, then the next stage of structured proportionality involves asking whether the means used to achieve that legitimate purpose are reasonably necessary for achieving that purpose. As in the context of the implied freedom of political communication[435], the question of reasonable necessity in relation to s 92 will be assessed according to the availability and obviousness of means that could achieve the same legitimate purpose to the same extent but without burdening, or with a lesser burden on, the freedom guaranteed by s 92.

     [435]See McCloy v New South Wales (2015) 257 CLR 178 at 210 [57]; Clubb v Edwards (2019) 267 CLR 171 at 336-338 [476]‑[480].

272. In Cole v Whitfield[436], this Court said that even if the law had conferred an advantage on local trade it would have been justified because the regulation was a "necessary means" of enforcing the prohibition against catching undersized crayfish. But, without the qualification of "reasonableness", a requirement for necessary means might be misunderstood as a test of the ingenuity of counsel. It might imply that a defendant could not justify a law if, as could have been done in this case, counsel for the party challenging the law could identify any manner by which the law's objects could be achieved by any other, less restrictive means. That consequence is avoided by the decisions on s 92 which clarified that this consideration is concerned with whether the law burdens the freedom by means that are more restrictive than is "reasonable" to achieve its purposes[437].

     [436](1988) 165 CLR 360 at 409.

     [437]Uebergang v Australian Wheat Board (1980) 145 CLR 266 at 306; Castlemaine Tooheys Ltd v South Australia (1990) 169 CLR 436 at 469, cf at 480 ("alternative means involving no or a lesser burden"). See also AMS v AIF (1999) 199 CLR 160 at 179 [45], 233 [221]; APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322 at 353 [38], 393-394 [177], 461 [420].

273. In Betfair Pty Ltd v Western Australia[438], consistently with earlier decisions[439], six members of this Court said in a joint judgment that the enquiry should be described as one of "reasonable necessity" and that these terms should be "accepted as the doctrine of the Court". In that case, a Western Australian law was held not to be "proportionate" because it was not shown to be reasonably necessary. As the joint judgment explained, there was an apparent legislative alternative, taken by Tasmanian law, which did not involve discrimination[440]. This description of "reasonable necessity" has been correctly described as a "mirror", to an extent, of the same enquiry in the context of structured proportionality analysis used in relation to the implied freedom of political communication[441].

     [438](2008) 234 CLR 418 at 477 [102]-[103].

     [439]See North Eastern Dairy Co Ltd v Dairy Industry Authority of NSW (1975) 134 CLR 559 at 584; Cunliffe v The Commonwealth (1994) 182 CLR 272 at 308.

     [440]Betfair Pty Ltd v Western Australia (2008) 234 CLR 418 at 479 [110].

     [441]McCloy v New South Wales (2015) 257 CLR 178 at 210 [57]. See also Unions NSW v New South Wales (2019) 264 CLR 595 at 615 [42].

274. It should be emphasised that reasonableness is not a monolithic standard[442]. In other areas it is now accepted that the threshold of reasonableness, or intensity of review, can vary between different categories of case[443]. It is enough in this case to say that in the context of s 92 the reasonableness threshold means there will be a margin of appreciation afforded to Parliament before its legislation will be found to fall outside the boundaries of choice of the means by which to implement the legislative purpose.

     [442]See Minister for Immigration and Border Protection v SZVFW (2018) 264 CLR 541 at 567 [59], 574 [84], 584-586 [133]‑[135]; Clubb v Edwards (2019) 267 CLR 171 at 336-337 [477].

     [443]Minister for Home Affairs v DUA16 (2020) 95 ALJR 54 at 61 [26].

     Proportionality stage three: adequacy in the balance 

275. The final stage of structured proportionality is perhaps the most controversial. It requires asking whether the law is adequate in its balance[444]. Even if the means adopted by the law are reasonably necessary to achieve its purpose, there will be some cases where the purpose of the law is nevertheless not of sufficient importance to justify the burden that the law places on interstate trade, commerce, or intercourse given the high importance and purpose of s 92 of the Constitution. A law will be inadequate in the balance if, notwithstanding that the law is the only reasonable means of achieving the purpose, the extent of the discrimination and thus the incursion into the freedom of trade, commerce, or intercourse cannot be justified given the purpose of the law[445].

     [444]See Clubb v Edwards (2019) 267 CLR 171 at 208 [96], 209 [102], 266-267 [270], 341-344 [491]-[498]; Comcare v Banerji (2019) 93 ALJR 900 at 914 [38], 936 [165]; 372 ALR 42 at 57, 88.

     [445]cf Clark King & Co Pty Ltd v Australian Wheat Board (1978) 140 CLR 120 at 191‑193.

276. Considerations of high public policy are involved in this balancing of, on the one hand, Parliament's purpose and, on the other hand, the importance of freedom of trade, commerce, and intercourse and the extent to which that freedom is burdened. A foundational principle of the Constitution is representative democracy, which generally requires that significant policy decisions be left to the branch of government best suited to make them: the Parliament. However, the description of the s 92 freedom as "absolute" supports the possibility of invalidity where Parliament puts a necessary but extreme burden on the subject matter of s 92 in order to achieve a purpose that is trivial, usually assessed by reference to the context and importance that Parliament itself has placed on the purpose.

     Sections 56 and 67 of the Emergency Management Act are justified in their relevant application

     Sections 56 and 67 serve a legitimate purpose

277. The plaintiffs' central submission alleged a substantial identity between the Quarantine (Closing the Border) Directions and the Restriction of Interstate Passenger Transport Order held by this Court to be invalid in Gratwick v Johnson[446]. The primary legislation considered in Gratwick was an open-textured wartime power under the National Security Act 1939 (Cth) to make regulations for securing the public safety and defence of the Commonwealth. The regulations made included the National Security (Land Transport) Regulations (Cth), under which a power was exercised to pass the Restriction of Interstate Passenger Transport Order, which, in para 3(a), prohibited travel by rail or commercial passenger vehicle from one State to another without a permit. The Order did not "depend ... for its practical operation or administration upon the movement of troops, munitions, war supplies, or any like considerations". It was "simply based on the 'inter-Stateness' of the journeys"[447]. On the questionable assumption that the Order would otherwise have been permitted by the primary legislation and regulations, it was held to be invalid. It might have been more accurate to have held the primary legislation invalid insofar as it authorised regulations that would permit such an order. But the key point is that the purposes, not merely the effect, of the Order included discriminating between intrastate and interstate intercourse.

     [446](1945) 70 CLR 1.

     [447]Gratwick v Johnson (1945) 70 CLR 1 at 19.

278. The plaintiffs also relied upon the decision in R v Smithers; Ex parte Benson[448], where this Court considered the prohibition in s 3 of the Influx of Criminals Prevention Act 1903 (NSW) upon certain criminals entering New South Wales from other States. This Court held that the provision was invalid. Isaacs and Higgins JJ did so on the ground that the provision contravened s 92 of the Constitution. Isaacs J described s 92 as an "absolute prohibition on the Commonwealth and States alike to regard State borders as in themselves possible barriers to intercourse between Australians"[449]. Higgins J spoke of how the legislation was "pointed directly at the act of coming into New South Wales"[450]. A natural understanding of these passages, and an explanation for the result, is that s 92 imposes an absolute prohibition upon laws with the object, and not merely the effect, of burdening interstate intercourse. Although one object of s 3 was to reduce the number of criminals in New South Wales, the reasoning of Isaacs and Higgins JJ seemed to be that another object (or, as Isaacs J put it, the "regard" of the State), and not merely an effect, was to discriminate between intrastate intercourse for criminals within New South Wales and interstate intercourse for criminals outside New South Wales.

     [448](1912) 16 CLR 99.

     [449]R v Smithers; Ex parte Benson (1912) 16 CLR 99 at 117.

     [450]R v Smithers; Ex parte Benson (1912) 16 CLR 99 at 118 (emphasis in original).

279. The result in both of these decisions is consistent with the approach to s 92 since Cole v Whitfield, which invalidates a law whose purpose is the very thing that s 92 prohibits: discriminating between the States in relation to intercourse. That is not the case with ss 56 and 67 of the Emergency Management Act.

280. Section 56 of the Emergency Management Act was part of the legislation when it was passed in 2005. Its purpose was "to put appropriate arrangements in place to deal with the catastrophic natural or man-made emergencies that may befall our state"[451]. Section 67 was also part of the 2005 Act but it was amended in 2020 in response to what was described in Parliament as the "unprecedented emergency" after "a state of emergency was declared [on 15 March 2020] in respect of the pandemic caused by COVID-19"[452]. In each case the manifest purpose was to create, and to make conditional, broad powers for the Minister to manage a broad range of emergencies.  

     [451]Western Australia, Legislative Assembly, Parliamentary Debates (Hansard), 17 August 2005 at 4120.

     [452]Western Australia, Legislative Assembly, Parliamentary Debates (Hansard), 31 March 2020 at 1824.

     The discrimination in ss 56 and 67 is reasonably necessary

281. Even where the purpose of a statutory provision concerns a matter of great public importance, the provision will contravene s 92 if its effect is to impose an excessive discriminatory burden by means which are not reasonably necessary. For instance, in Tasmania v Victoria[453] a majority of this Court held invalid an application of s 4 of the Vegetation and Vine Diseases Act 1928 (Vic) which empowered proclamations to prohibit the importation into Victoria of any tree, plant or vegetable which, in the opinion of the Governor in Council, is likely to introduce any disease or insect into Victoria. In a conclusion which would be equally appropriate to the application of the test now accepted for s 92, and in a context in which few vegetables were immune from liability to some disease, Dixon J said that it is absurd to suppose that a State could legislate to provide it with a power[454]

     "entirely uncontrolled to forbid absolutely the importation of a commodity from another State because the State Executive expresses the opinion that a vegetable disease may be introduced if importation is allowed".

     [453](1935) 52 CLR 157.

     [454]Tasmania v Victoria (1935) 52 CLR 157 at 186.

282. Sections 56 and 67, in their limited application to a state of emergency constituted by the occurrence of a hazard in the nature of a plague or epidemic, might empower directions which discriminate in an extraordinary way in relation to freedom of trade, commerce, or intercourse. For instance, within the sphere of application of this Court's answer, the sections appear to empower directions as restrictive as closing all roads and access routes to Western Australia for all purposes and without exception. Such a closure would amount to an impregnable and absolute discriminatory barrier to all trade, commerce, and intercourse that required dealings in person or the contemporaneous transfer of physical things. But despite the possibility of severe discriminatory effects, the terms of ss 56 and 67, in their application as limited in the answer given by this Court, do not exceed the threshold of reasonable necessity because of several significant restrictions.

283. First, an extreme direction such as that described above can only be made under s 67 if the Minister has declared a state of emergency[455]. That declaration cannot be made unless, relevantly, the Minister: has considered the advice of the State Emergency Coordinator[456]; is satisfied that an emergency in the nature of a plague or epidemic has occurred or is occurring[457]; and is satisfied that extraordinary measures are required to prevent or minimise loss of life, prejudice to the safety, or harm to the health, of people[458].

     [455]Emergency Management Act, s 56(1).

     [456]Emergency Management Act, s 56(2)(a).

     [457]Emergency Management Act, s 56(2)(b).

     [458]Emergency Management Act, s 56(2)(c).

284. Secondly, unless the state of emergency is extended by the Minister, which extension cannot exceed 14 days for the purposes of exercising powers under s 67[459], it remains in force for only three days[460].

     [459]Emergency Management Act, s 58(4).

     [460]Emergency Management Act, s 57.

285. Thirdly, directions made under s 67 must be "[f]or the purpose of emergency management" during the state of emergency. Section 3 defines "emergency management" as including matters relating to prevention of, preparedness for, response to, and recovery from, the adverse effects of an emergency, relevantly here the occurrence of a hazard in the nature of a plague or epidemic. The requirement that the directions given by an authorised officer be "[f]or the purpose of emergency management" is objective, unlike the subjectivity involved in the proclamation power in Tasmania v Victoria. Although "purpose" bears its usual meaning in this context, namely object or aim, the constraint is significant because the less reasonably necessary an extreme direction is (such as closing all roads without exception) the more likely it is that an inference will be drawn that the direction is not solely for the purpose of emergency management.

286. Fourthly, although s 67, unlike s 66(3), does not expressly provide that directions must be "reasonably required for the purposes of emergency management" (emphasis added), the usual implication of reasonableness would confine the discretion of the authorised officer to make directions that are reasonable in light of the purpose of emergency management. Nevertheless, the nature of this usual implication, and the extreme nature of the circumstances in which the power is being exercised, might require the threshold for a finding of legal unreasonableness of any direction to be higher than that which might be conveyed by an express condition of being "reasonably required" for the purpose of emergency management[461].

     [461]Minister for Home Affairs v DUA16 (2020) 95 ALJR 54 at 61 [26].

287. The legislative response by Western Australia might have been more limited with less intrusion into the freedom prescribed by s 92. Some simple examples are that the extension of a state of emergency might have been limited to seven days and the power to make directions under s 67 might have been expressly limited to those that are reasonably required. But the existence of such possible lesser intrusions upon the s 92 freedom does not mean that ss 56 and 67 of the Emergency Management Act are invalid in their relevant applications for two reasons. First, although ss 56 and 67 permit applications that burden substantially the s 92 freedom, by allowing for both a wide range of directions that could discriminate and a considerable depth or extent of discrimination, the purpose of the provisions – responding to emergencies – requires a great deal of flexibility. It might be expected that the loss of that flexibility by provisions involving a lesser burden would prevent Parliament's purpose being achieved to the same degree. In other words, the lesser intrusions might not achieve Parliament's purpose to the same degree. Secondly, and in any event, ss 56 and 67 in their particular applications identified by this Court are well within a margin of reasonable legislative responses that minimise the intrusions upon the s 92 freedom.

     The burden imposed by the Emergency Management Act is adequate in the balance

288. In the context of s 92, a test for adequacy in the balance effectively asks whether the extent of the burden that the law imposes upon the freedom that is prescribed by s 92 can ever be justified by that law's purpose. In other words, the balance is between, on the one hand, the importance of the constitutional freedom of trade, commerce, and intercourse and the extent to which that freedom is burdened by the law and, on the other hand, the purpose of the law that is said to justify that burden. I reiterate that this stage of analysis will only lead to a conclusion of invalidity in extreme circumstances: a conclusion that the law is inadequate in the balance comes very close to saying that Parliament can never legislate to achieve its policy since even a law that is reasonably necessary to achieve that purpose will be invalid.

289. The important purpose of the freedom of interstate intercourse is well summarised by the description by Sir Samuel Griffith of the expected benefits of free intercourse[462]:

     "The effects, both social and material, of such an enlargement of knowledge and extension of movement could not fail to be highly beneficial. The present lack of more general acquaintance and intercourse is, indeed, probably one of the most serious obstacles now existing in the way of Federation."

     [462]Griffith, Notes on Australian Federation: Its Nature and Probable Effects (1896) at 33.

290. An example of a law whose purpose might be considered inadequate when balanced against the weight of the purpose of s 92 and the extent of the burden effected by the law is one which was considered to be "at the least doubtful" in 1903 by Mr Deakin, then Attorney-General of the Commonwealth[463]. Tasmanian legislation[464] imposed a charge for the admission to Tasmania of various categories of person including those who were unable to support themselves or who were likely, "in the opinion of the Collector, to become a charge upon the public". Even assuming that the purpose of decreasing the financial burdens to the State of persons in that relevant class was a legitimate purpose, that purpose might be inadequate in the balance against the discriminatory effect of the law and its undermining of the purpose of s 92. Hence, even if there were no other reasonably available means of reducing those costs, this legislation might be invalid.

     [463]See Brazil and Mitchell (eds), Opinions of Attorneys-General of the Commonwealth of Australia (1981), vol 1 at 172-173.

     [464]Passengers Act 1885 (Tas), s 3.

291. By contrast, the purpose of public health provisions such as ss 56 and 67 is plainly sufficient to justify even the deep and wide burden that the application of those provisions can place upon the freedom prescribed by s 92. Indeed, at federation it was contemplated that the application of provisions of this nature might be justified despite the imposition of such deep or wide burdens. During the Sydney debates, after one of the delegates, Dr Cockburn, expressed a fear that the clause as drafted might prevent laws prohibiting the passing of cattle across State borders or the introduction of diseased vines into South Australia, Mr O'Connor, quoting from a prolific writer from the United States[465], set out a good description of the operation of structured proportionality in this area[466]:

     "By parity of reason addressed to the protection of the public health, states may exercise their police powers to the extent of prohibiting both persons and animals, when labouring under contagious diseases, from entering their territory. They may pass any sanitary laws deemed necessary for this purpose, and enforce them by appropriate regulations. It is upon this reserved right of self-protection, that quarantines are permitted to interfere with the freedom of commerce and of human intercourse. But this power is not without its limitations, and its exercise must be restricted to directly impending dangers to health, and not to those who are only contingent and remote. Hence, while diseased persons or diseased animals, and those presumedly so from contact with infected bodies or localities, may be prevented from entering a state, any general law of exclusion, measured by months, or operating in such a way as to become a barrier to commerce or travel, would be a regulation of commerce forbidden by the constitution. Such a statute being more than a quarantine regulation, transcends the legitimate powers of a state."

     [465]Ordronaux, Constitutional Legislation in the United States: Its Origin, and Application to the Relative Powers of Congress, and of State Legislatures (1891) at 296-297.

     [466]Official Record of the Debates of the Australasian Federal Convention (Sydney), 22 September 1897 at 1062.

292. Subsequently, Mr Barton said, in terms reflecting the first stage of structured proportionality, that "the power to prevent the introduction of diseases would still remain with the states, except in so far as any state law was found to be an intentional derogation from the freedom of trade"[467].

     [467]Official Record of the Debates of the Australasian Federal Convention (Sydney), 22 September 1897 at 1064.

     Conclusion

293. For these reasons, I join in the orders that were made on 6 November 2020.