Citizenship deprivation as banishment: The High Court of Australia in Alexander’s case

Rayner Thwaites (University of Sydney)


On 8 June 2022 the Australian High Court invalidated a ministerial power of citizenship deprivation, declaring that the applicant, the subject of a determination under the relevant provision of the Australian Citizenship Act, remained an Australian citizen. The decision in Alexander v Minister for Home Affairs [2022] HCA 19 (‘Alexander’s case’) is the first Australian decision on powers enabling deprivation for ‘disallegiant’ conduct.

The High Court of Australia reasoned that the citizenship deprivation was punishment for misconduct. Punishment for misconduct is an exclusively judicial function, one that cannot be conferred on the executive. The ministerial power breached the separation of powers and was accordingly constitutionally invalid.

In essence, the majority, six of seven members of the Court,[1] characterised citizenship deprivation as banishment; a punishment with serious effects. This characterization of deprivation as punishment rested on a view of citizenship status as a fundamental assurance of territorial security.

The facts and legal context

Powers of citizenship deprivation for ‘disallegiant’ conduct, defined with reference to terrorism offences, were first enacted in Australia in December 2015. This was in response to concerns about ‘foreign fighters’; Australians returning from fighting for ISIS in Syria and Iraq.

The applicant in the case, Delil Alexander, is a dual Australian-Turkish national. He acquired both citizenships by birth, the first by birth in Australia, the second by descent. He left Australia for Syria in 2013. The Australian Security Intelligence Organisation (‘ASIO’) reported that it was ‘likely’ that Mr Alexander had joined ISIS there by August of that year. Apprehended by Kurdish militia in November 2017 he was transferred to Syrian authorities. In July 2020 he was transferred to a prison run by the Syrian intelligence organisation. This was despite an earlier pardon for convictions against the Syrian criminal code. His family and lawyers have not heard from him since July 2021 (the month he was purportedly deprived of his Australian citizenship). His sister initiated the High Court proceedings on his behalf.

The Minister of Home Affairs determined to deprive him of his citizenship on 2 July 2021, pursuant to a discretion conferred by s 36B of the Australian Citizenship Act, a section inserted by amendments in September 2020. The section empowered the Minister to deprive a dual citizen of their Australian citizenship where she was satisfied that: (a) the person had engaged in the proscribed conduct (loosely and problematically defined with reference to various terrorism offences in the criminal code); (b) the conduct demonstrated that the person had ‘repudiated their allegiance to Australia’ and; (c) ‘it would be contrary to the public interest for the person to remain an Australian citizen’. The particular conduct relied on in Mr Alexander’s case was ‘foreign incursions and recruitment’. Section 36B provided that this phrase had the ‘same meaning’ as in s 119.2 of the Criminal Code, which made it an offence for an Australian citizen to enter or remain in an area of a foreign country that was the subject of a declaration by the Minister for Foreign Affairs. Al-Raqqa province, Syria, had been the subject of such a declaration for three years from 5 December 2014, with ASIO reporting that Mr Alexander had likely entered the province in the relevant period. The conduct that the Minister had to be satisfied of comprised only the conduct element of the relevant criminal code offences. The mental elements of the offences did not apply to section 36B.

The operative reasoning: the separation of judicial power

The result in Alexander’s case hinges on issues of judicial power, more particularly the exclusive conferral of judicial power on courts under the Australian Constitution. To analogise to a more widely known constitutional jurisprudence, that of the United States (‘US’), the issues go to questions of due process (see references to US jurisprudence below). I outline the Court’s reasoning on judicial power, the better to situate its statements on citizenship and the decision’s practical implications.

The Australian Constitution provides, among other matters, for the national Parliament and legislative power in Chapter I, the executive in Chapter II, and the federal judiciary in Chapter III. Chapter III has been held to make exhaustive provision for the exercise of judicial power in federal matters. While there is a complexity of rules, the principal rule here is that judicial power in federal matters is exclusive to courts. ‘Federal matters’ in this context refers to matters described in sections 75 and 76 of the Constitution as falling within federal jurisdiction.

In Lim’s case (1992), a decision on immigration detention, the High Court held that:

There are some functions which, by reason of their nature or because of historical considerations, have become established as essentially and exclusively judicial in character. The most important of them is the adjudgment and punishment of criminal guilt under a law of the Commonwealth. ([22] per Brennan, Deane and Dawson JJ).

Over the thirty years to Alexander’s case, this proposition had been applied to executive detention. Involuntary detention by the executive, in the absence of a legitimate non-punitive purpose, was held to constitute punishment, and would be held constitutionally invalid on that basis. The ‘key move’ in Alexander’s case was to extend the application of this proposition – to citizenship deprivation. The majority judgments presented citizenship deprivation as, prima facie, a more serious punishment than detention. Not only did one lose one’s liberty, but all entitlement to be in the community.

In emphasizing the character of deprivation as a punishment, and its gravity, members of the majority drew extensively, among other matters, on the historical use of exile and banishment as punishments. They analysed the detail of the statutory regime. They also referenced US Supreme Court decisions on citizenship deprivation, taken from a period in which due process reasoning was the Supreme Court’s primary line of response to deprivation.[2]

The ‘fundamental importance’ of citizenship

The characterisation of deprivation as punishment was underwritten, in ways crucial to the reasoning, by the importance attached to citizenship. The rights attending citizenship were said to be ‘public rights of “fundamental importance” to the relationship between the individual and the Commonwealth [Australia’s national government]’ [74] (citations omitted from all quotes):

For an Australian citizen, his or her citizenship is an assurance that, subject only to the operation of the criminal law administered by the courts, he or she is entitled to be at liberty in this country and to return to it as a safe haven in need [74].

The value of citizenship as expressed here is constituted by the constitutional vulnerability of non-citizens. The statement that citizenship carries an entitlement to ‘to be at liberty in this country’ stands out in sharp relief against the position of non-citizens. Legislation has for decades specified that a non-citizen in Australia without a visa is there unlawfully and subject to mandatory immigration detention. The primary constitutional constraint on immigration detention is drawn from the Lim principle, quoted above. It allows for executive detention for a ‘legitimate non-punitive purpose’. Immigration detention for the purpose of processing, the making of a decision to process, and removal, has been held to be a ‘legitimate non-punitive purpose’, with the bounds of immigration detention drawn very widely indeed.

To select one other aspect of the Court’s treatment of citizenship – the government had argued that what was important was that a person had ‘a’ citizenship. Mr Alexander would be left with Turkish citizenship if deprived of the Australian status. The lead judgment rejected the government contention,[3] ruling that stripping away the rights ‘involved in Australian citizenship’ was a ‘serious punishment’, and that was so ‘whatever rights may be conferred by citizenship of another country’ [95]. Citizenships were not fungible.

The practical implications of Alexander’s case

The decision invalidated the ministerial deprivation power in s 36B, described above. The decision was delivered not long after the first change of government in nine years, following an election on 21 May 2022. The new Labor government has signalled that it perceives no need to ‘replace’ s 36B as there are alternatives already in place, adequate to regulating the return of ‘foreign fighters’. These include Temporary Exclusion Orders (TEOs) (which can delay and condition the return of Australian citizens) and Control Orders (authorising restrictions short of detention).

The decision leaves open the fate of other deprivation mechanisms under the Australian Citizenship Act. Confining attention to mechanisms directed at ‘disallegiant’ conduct, s 36D provides for a ministerial power of deprivation conditioned on prior conviction and sentence by a court with respect to a nominated set of terrorism offences. The application of Alexander’s case to this provision will turn on whether, in authorising citizenship deprivation, s 36D ‘authorises the imposition of a new or additional punishment for a person committing an offence’ [174].

Then there is the question of those deprived of Australian citizenship between December 2015 and September 2020. The main mechanism used in this period relied on a legal fiction of automaticity. Persons were stripped of their Australian citizenship ‘automatically’ by operation of the statute when they engaged in proscribed conduct, apparently without the involvement of any decision-maker. The transitional provisions contained in the September 2020 amendments deemed the relevant pre-amendment deprivation decisions to have been made under s 36B. Prima-facie, this means they have now been invalidated.

A wide range of other issues are traversed in the judgments, including the relationship between citizenship (a statutory status in Australia) and constitutional membership, the role of allegiance in legal reasoning and what might constitute ‘disallegiant’ conduct, and why a purpose of ‘protection of the community’ did not (or, for the dissent, did) make deprivation non-punitive in the circumstances.

Cases on citizenship and constitutional membership have been coming before the Australian High Court with regularity over the last five or so years (for example, see Re Canavan and Love and Thoms), with little sign of slowing. The social and legal context for Australian citizenship has changed over time and these changes now generating questions for Australian constitutional doctrine.


[1] The decision comprised five separate judgments. Four for the majority and a dissent.

[2] Notably Kennedy v Mendoza-Martinez (1963) 372 US 144 and Trop v Dulles (1958) 356 US 86.

[3] The lead judgment comprised three judges, and was endorsed by a fourth, constituting a majority of the seven judges to explicitly address the point in these terms.


Featured image: High Court of Australia (CC BY 2.0)