Convicted terrorist Abdul Nacer Benbrika could be released from prison in the next eight weeks after he successfully appealed against the stripping of his Australian citizenship in the high court.
The decision of a majority of the court on Wednesday struck down another part of Coalition-era powers, following a similar ruling in June 2022 that found suspected terrorists cannot be punished by ministers removing their citizenship.
Benbrika, an Algerian-born cleric, was convicted of terror offences in 2008 and was due for release in 2020, but has since remained in detention under a controversial post-sentence detention regime.
His current detention order expires on 24 December.
The Victorian supreme court is expected to deliver a ruling before this date on whether Benbrika should be released on an extended supervision order, which would permit his release under strict conditions.
Just before his sentence was due to expire in 2020, the then home affairs minister Peter Dutton cancelled his citizenship using recently introduced powers. The laws gave broad power to the minister to revoke a person’s citizenship after they were convicted of a terror offence.
Benbrika argued that the laws were not constitutional as they gave the minister powers that should be reserved for the judiciary – namely, the power to punish someone for criminal conduct.
“The fact that a court determines some, though not all, of the facts and circumstances that are relevant to engaging the power … does not deny that the minister has purportedly been authorised to punish a person by way of involuntary deprivation of citizenship,” his lawyers had argued.
But lawyers for the commonwealth argued that the powers did not give the minister powers exclusively reserved for the courts. It did not require a minister to engage in fact-finding, deliver judgment or pass sentence, they argued. The powers to strip citizenship from individuals like Benbrika only became available after a court had already convicted and sentenced an individual for a terror offence.
The commonwealth solicitor general, Stephen Donaghue KC, told a high court hearing in June that it was not then unprecedented that an individual convicted and sentenced for an offence would then be subject to additional punishment.
“That there are circumstances where, after a person has been convicted and punished, additional punishment can be imposed, is not an unprecedented idea,” he said. “Forfeiture is an example of that very thing occurring.”
In June 2022 the high court restored the Australian citizenship of Delil Alexander, a Turkish citizen who was assessed to have joined Islamic State. The court found powers to strip citizenship gave the minister a role in adjudging and punishing criminal guilt, something that should be reserved only for courts.
On Wednesday the high court similarly found in Benbrika’s favour in what it described as a “sequel” to Alexander’s case, ruling that section 36D of the Citizenship Act is invalid as it confers powers to the minister that should be exclusive to the judiciary.
The majority – made up of the chief justice, Susan Kiefel, and justices Stephen Gageler, Jacqueline Gleeson and Jayne Jagot – said that Benbrika’s submission that the power in 36D was “indistinguishable” from the one struck down in Alexander’s case was “unanswerable”.
They ruled that the separation of powers in the constitution makes “punishment of criminal conduct exclusively judicial even if the punishment is separated from the adjudication of that criminal guilt”.
Parliament cannot give ministers “any power to impose additional or further punishment” on people convicted of offences, they said.
In a dissenting ruling, justice Simon Steward agreed with the commonwealth that it has “never been an essentially judicial function to make orders which denationalise a person”.
Steward said the purpose of citizenship cancellation “is not to sanction proscribed conduct” but rather “recognition that by extreme conduct that person has inexorably separated themselves from the people as a community and from Australia itself”.
Steward noted findings by the trial judge in 2009 that there was “no evidence” before that court that “Benbrika has, in any way, renounced his commitment to violent jihad and hence to terrorism”.
Steward concluded that “cancellation here is simply … acknowledgment of something which has in fact already occurred: a person’s rejection of membership of the Australian body politic”.
The decision is expected to be key in shaping the Albanese government’s planned new citizenship laws. The government has previously pledged to give courts the power to strip citizenship for dual citizens over terrorism conduct or a terrorism conviction, but the proposal has been on hold pending the high court decision.
On Wednesday the prime minister, Anthony Albanese, said the government will “examine the ruling and respond appropriately”.
“Quite clearly there was an issue with the former government’s legislation, which is what this ruling relates to,” Albanese said.
The acting opposition leader, Sussan Ley, described Benbrika as a “convicted terrorist who [had] planned to conduct attacks on Australian soil”.
Ley said the ruling was a “real test” for the government to “have legislation when we go back into the parliament in mid-November”.
The shadow foreign minister, Simon Birmingham, offered “full bipartisan cooperation” from the Coalition for “actions that may be necessary, legislatively or otherwise, to keep Australians safe”.
Birmingham called on the Albanese government to “act with urgency to ensure that Mr Benbrika can pose no threat to Australia, to ensure his continued detention, and to look at whatever means are necessary to keep Australians safe.”
