This is one of a special series of posts exploring the public law implications of the COVID-19 pandemic. For more information on the Gilbert + Tobin Centre’s work in the area of public law and public health, see here.


On 5 April 2020, the Western Australian border was closed. Pursuant to powers created by the Emergency Management Act 2005 (WA), the WA State Emergency Coordinator issued the Quarantine (Closing the Border) Directions (the ‘Directions’), which prevented entry to Western Australia by any non-‘exempt traveller’. The Directions were issued as part of the WA Government’s response to SARS-CoV-2 and its associated disease, COVID-19.

Clive Palmer, intending to travel into WA, was denied a travel exemption on 22 May. Mr Palmer then filed a challenge to the constitutional validity of the Directions in the High Court, arguing that the Directions contravene s 92 of the Australian Constitution. On 18 June, the High Court remitted the matter to the Federal Court, where Rangiah J will make several determinations of fact based on the arguments of both parties. The hearing in the Federal Court began on Monday 27 July, and once the decision is delivered a full bench of the High Court will consider the validity of the WA border closure. The Commonwealth had originally intervened to join Mr Palmer in the matter, but withdrew its support after the four-day trial concluded.

This post examines the nature of s 92, briefly explains the status of Mr Palmer’s challenge to the WA border closure, and surveys two interesting issues raised by Mr Palmer’s claim in the context of COVID-19. Those issues concern the extent to which physical travel remains a necessity for interstate trade and commerce, and the extent to which a court can rely upon expert epidemiological evidence regarding the COVID-19 pandemic.

Section 92

Section 92 of the Australian Constitution relevantly states that:

On the imposition of uniform duties of customs, trade, commerce and intercourse among States … shall be absolutely free.

While this section appears straightforward on its face, interpretation of the phrase ‘absolutely free’ has given rise to the most confused jurisprudence in High Court history. For decades, the High Court was unable to agree on the underlying basis of s 92. Do the words ‘absolutely free’ mean that the section protects the right of individual Australians to trade across and move through state borders, as Barwick CJ held in Uebergang v Australian Wheat Board (1980)? Does s 92 only prevent the imposition of fiscal burdens on interstate trade, commerce, and intercourse, as Murphy J said in Buck v Bavone (1976)? Or does s 92 relate to wider economic concepts, such as the promotion of free trade and the prevention of state protectionism?

A unanimous High Court answered these questions in Cole v Whitfield (1988), holding that s 92 enshrines the notion of free trade and prohibits the imposition of ‘discriminatory burdens of a protectionist kind’. According to the High Court, a law cannot discriminate in a protectionist way as regards interstate trade and commerce, by either legal or practical operation. Furthermore, the reference to interstate ‘intercourse’ was treated by the High Court as separate to the reference to ‘trade and commerce’ (though the High Court did not need to explain the nature of the guarantee of interstate intercourse in Cole v Whitfield). Thus, s 92 contains two limbs: the first protects interstate trade and commerce, while the second protects interstate intercourse. The latter is generally understood as protecting freedom of movement across Australian state borders.

a) Freedom of interstate trade and commerce

A challenge to the validity of a law on the ground that the law impermissibly burdens the freedom of interstate trade and commerce is an allegation that the law is both discriminatory and protectionist. In the first sense, the law must apply to interstate and intrastate trade and commerce unequally. In the second, the law must protect intrastate business from interstate competition. Both qualities are determined as a matter of fact and degree; s 92 does not provide an absolute freedom in the literal sense, despite its wording.

It is uncontroversial that a law which openly seeks to benefit intrastate trade and commerce at the expense of interstate trade and commerce impermissibly burdens the freedom. However, difficulty arises when it is a law aimed at a different, legitimate object that burdens interstate trade and commerce. In these cases, the issue becomes one of characterisation: is the law, properly characterised, one which impermissibly burdens the freedom of interstate trade and commerce despite its legitimate object? The High Court considered this question of characterisation in Castlemaine Tooheys v South Australia (1990) (‘Castlemaine Tooheys’).

In Castlemaine Tooheys, the plurality noted the importance of considering the manner in which a law aimed at a legitimate object imposes a discriminatory burden upon interstate trade and commerce. According to the High Court, whether a law gives effect to discrimination prohibited by s 92 can be determined by examining the relationship between the object of the law and the practical consequences of the law for interstate trade and commerce. If a ‘reasonable, non-discriminatory alternative means of securing [the] legitimate object’ exists, then the law may be properly characterised as giving effect to the discrimination prohibited by s 92. The guarantee contained in s 92 therefore requires a focus upon whether the practical operation of a law is ‘appropriate and adapted’ to the law’s legitimate object.

The High Court again considered this process of characterisation in Betfair v Western Australia (2008). A six-judge plurality held that an examination of the relationship between the legitimate object of a law and that law’s consequences for interstate trade and commerce requires consideration of the notion of ‘reasonable necessity’. This notion is best known to the public law in its role as part of ‘structured proportionality’ testing. However, it remains unclear whether structured proportionality—a model of reasoning that involves considering suitability, necessity and balance—is appropriate for use as an aid to characterisation. Indeed, in a later case (Betfair v Racing New South Wales (2012)), a plurality of the High Court indicated that s 92 will permit any protectionist discrimination if that discrimination is reasonably necessary to the achievement of a legitimate non-protectionist purpose.

b) Freedom of interstate intercourse

The second limb of s 92 has not been given as much attention as the first. The High Court has stressed that the freedom of intercourse does not, necessarily, correspond in meaning to the freedom of trade and commerce. Nonetheless, the High Court appears to assess any interference in the freedom of interstate intercourse in much the same way as interference in interstate trade and commerce.  In APLA Ltd v Legal Service Commissioner (NSW) (2005), Gleeson CJ and Heydon, Hayne, and Gummow JJ enquired into whether the relevant regulation infringed the freedom of interstate intercourse by considering whether the impediment to interstate movement was more than what was ‘reasonably required’ to achieve the object of the regulations.

c) Palmer v WA and necessity

Mr Palmer’s challenge in the High Court to the validity of the Directions will depend chiefly upon an argument that the decision to close the WA border is not reasonably necessary in the WA government’s response to COVID-19.  Mr Palmer will argue that both the freedom of interstate trade and commerce, and interstate intercourse, are burdened unnecessarily. This argument is predicated on an assertion that the WA government could have attained the object of the Directions without closing the border. In assessing this claim, several questions of fact arise. Do border closures actually prevent the spread of COVID-19? Are there other measures that could prevent the spread of COVID-19? What would happen if the border were re-opened?

In light of the complicated epidemiological evidence required to determine the necessity of the border closure, Palmer v WA has initially been heard by Rangiah J in the Federal Court. Justice Rangiah has been asked to determine ‘the reasonable need for and efficacy of the community isolation measures contained in the Quarantine (Closing the Border) Directions’. Justice Rangiah’s findings will form the basis of the High Court’s consideration of the legality of the border closure.

The unique issues raised by Palmer v WA

The application of s 92 raises at least two interesting evidentiary questions in Palmer v WA.  The first is the degree to which interstate trade and commerce is affected by a physical border closure, despite the availability of communication and commerce over the internet. The second is how the Court will approach evidence relating to COVID-19.

a) Is interstate travel necessary to conduct business?

To show that interstate trade and commerce has been burdened, Mr Palmer is arguing that businesses with their head offices outside Western Australia will be commercially disadvantaged when compared to those that have them inside Western Australia. He has standing to do so because this is the case for his own mining company, Minerology, which is joined with him to the proceedings and is headquartered in Queensland.

An argument on this ground might have been straightforward at Federation, when almost all business was conducted in-person. Yet today, a large amount of Australian commercial activity takes place remotely, a situation which has been intensified in light of restrictions imposed by the COVID-19 pandemic. The High Court itself has operated via video-connection for several months, demonstrating that interstate work can continue without physical travel. In this peculiar moment of digital interconnectedness, the High Court may be less inclined to find that the border closure burdens the freedom of interstate trade and commerce in the manner that Mr Palmer suggests.

Chief Justice Kiefel was alive to this possibility in the initial directions hearing, where she noted that Mr Palmer’s claim ‘would have to take account of the fact that we are living in somewhat of a digital age’. Nonetheless, before Rangiah J Mr Palmer has pressed the point that it is ‘detrimental to manage [a] business only through remote technology’. It may be that the Court is indirectly faced with a question on the minds of many in recent times: is remote work an adequate substitute for in-person operations?

A finding that digital connectivity can obviate the need for physical travel would set an interesting precedent for the interstate trade and commerce limb of s 92. Future litigants may need to consider the extent to which any burden on interstate trade and commerce is affected by an increasingly digitally connected society. As industries grow to accommodate remote work more readily—a development which seems inevitable in current conditions—constitutional challenges relying on the trade and commerce limb may face a higher threshold for success.

Of course, the interstate intercourse limb of s 92 means that the ability to physically cross the border will always retain significance. A litigant whose business is deemed to be viable online can still challenge a law on the grounds that it burdens their ability as an individual to move from one state to another. If the High Court finds that Minerology can be managed adequately from afar, Mr Palmer’s challenge may centre on the ‘intercourse’ limb of s 92. In this case, his inability to pass freely across the WA border would form the basis of his claim.

b) What weight can the Court give to information about the COVID-19 pandemic?

Determination of whether the WA border closure is a reasonably necessary response to COVID-19 will rest on evidence regarding the severity of the outbreak. The purpose of the trial before Rangiah J is to determine the facts which the High Court will eventually rely upon in assessing the legality of the border closure. In this regard, the Federal Court trial has focused on three expert reports on the COVID-19 outbreak.

Western Australia filed a report from Associate Professor Kamalini Lokuge, which likely supports the argument that there is an epidemiological justification for closing the border. Mr Palmer  filed a report from Associate Professor Sanjaya Senanayake, which likely suggests the WA government has suitable alternatives to a border closure. The Commonwealth filed reports from Professors Peter Collignon and Tony Blakely, presumably reaching similar conclusion to Professor Senanayake. It is significant that the Commonwealth filed two reports as an intervenor, suggesting that before it withdrew it took a more substantial role in opposing the border closure than the Attorney-General initially suggested.

These reports consider the severity of the outbreak and evaluate preventative measures from an epidemiological perspective. Given that they will form the basis of an assessment of the reasonable necessity of the border closure, it is likely that the case will turn upon how much weight each of the reports is given. In evaluating them, Rangiah J will face two novel issues.

The first is the broad lack of consensus in scientific perspectives on the pandemic. Whereas many topics can be adjudicated by courts on the basis of long-term academic consensus, the recent emergence of SARS-CoV-2 means there is little agreement among epidemiologists on how to address the current crisis, or even the way in which the virus is transmitted. Without stable metrics, it would seem difficult for the Court to rely wholly on the perspective of any of the experts in the trial.

The second is in the inherent changeability of the pandemic. It is trite to say that the situation develops unpredictably, day by day. As at 2 August 2020, there are seven active COVID-19 cases in Western Australia, but that figure could change very quickly. The infection rates examined in the reports may be used to either justify or invalidate the directions; but in either circumstance, developments in pandemic conditions after they are published could render their observations obsolete.

This problem also affects assessment of COVID-19’s presence outside WA. While the hearings to date have appeared to focus on WA’s internal conditions, it seems logical that the infection rate in the rest of the country is equally relevant to the question of necessity. That is, where there is a growing likelihood that those entering the state could spread the infection, the border closure becomes more justifiable. This is true notwithstanding a steady decline in WA’s infections before—or even during—the closure of the borders.

This being so, the recent resurgence of the virus in Victoria may be used by Western Australia to evidence a heightened importance of strict controls. On 9 July Rangiah J ordered that the Federal Court trial be delayed because one of the experts, Professor Lokuge, was called to Victoria to help deal with the developing outbreak of COVID-19. Mr Palmer, who challenged the decision to delay the trial, may view this as an inauspicious beginning.


As with many constitutional matters, this case is likely to have lasting effects. The eventual High Court decision may contain valuable guidance as to which sorts of events warrant infringements on the freedom, and whether communicative technology has reduced need for physical travel in commercial practice.

The decision will also have relevance beyond the parties to the matter. While the business of Mr Palmer’s mining operations in WA might not bear on the lives of everyday Australians, his success could remove the barrier for those in the east attempting to enter WA—including stranded family members attempting to return to their loved ones. Mr Palmer’s challenge may well result in a loosening of border restrictions without a sacrifice to the ability of the WA government to control COVID-19. As Kiefel CJ reminded us in the initial directions hearing, ‘it is always good to be optimistic in times such as these’.

Henry Cooney and Harry Sanderson are Juris Doctor students at the University of Western Australia.

Suggested Citation: Henry Cooney and Harry Sanderson  ‘Border Closures and s 92: Clive Palmer’s Quest to Enter WA’ on AUSPUBLAW (04 August 2020) <>