Attorney general Christian Porter says government may be able to legislate a new way to deport those who have committed crimes

The Morrison government is looking to sidestep the high court’s decision that Aboriginal non-citizens cannot be deported using the aliens power by using other powers instead, the attorney general has said.

Responding to the high court’s landmark decision on Tuesday, Christian Porter said he found “great strength of reasoning” in chief justice Susan Kiefel’s minority judgment and the government may be able to legislate to deport the “not very large” group of Aboriginal non-citizens who have committed crimes in another way.

In a four-to-three decision, the high court held that Aboriginal people with sufficient connection to traditional societies cannot be aliens and therefore are beyond the reach of existing deportation laws which depend on the aliens power in section 51 (xix) of the constitution.

Legal experts urge caution on high court ruling that Aboriginal Australians are not 'aliens' Read more

Porter told 6PR Radio on Wednesday the decision has “very significant, immediate ramifications for what might not be a very large group of people”.

Porter noted this group – “people who are born overseas, who aren’t Australian citizens, but may be able to show indigeneity and who are in Australia on a visa and commit an offence” would now “have to be treated differently from all other persons in the same circumstances” because they cannot be deported under existing law.

“So, it has a clear impact for that group of people and that policy of deporting people who’ve committed serious offences while on a visa and who are non-citizens,” he said.

“And we’ll be looking into ways in which we might be able to effect that policy, without reliance on the power that we previously were relying on, but we’ll look at that.”

Porter tacitly endorsed Kiefel’s view, saying her “minority reasoning was what I would have expected” but conceded the majority view would have implications for the federal government’s “program of pretty vigorous deportation of people that we consider represent a threat to the Australian community and Australian citizens”.

In his minority judgment, justice Stephen Gageler laid out a blueprint for how parliament could address the “complications and uncertainties” created for the maintenance of an “orderly immigration program” by reinstating its powers to deport Aboriginal non-citizens.

He said these could be addressed “by the commonwealth parliament reverting to the approach of relying on the power conferred by [section] 51(xxvii) to make laws with respect to ‘immigration and emigration’”.

“Alternatively, the commonwealth parliament might consider itself obliged to address them through racially targeted legislation enacted under s 51(xxvi) of the constitution [the race power].”

Gageler said on the “correct understanding” of the aliens power “neither is a course which the commonwealth parliament ought to be driven to take”.

Porter also acknowledged the judgment “may have broader implications”.

“It creates an entirely new category of people in terms of what the government can and can’t do,” he said, in reference to the new category of “belonger” – a non-citizen non-alien, recognised by the majority.

“Whether or not the principle has application in areas where the commonwealth relies on other heads of power, I think, is far less clear.”

Porter argued it was “not always an easy test” to determine if a person is Indigenous, citing the fact the court now requires a further hearing to determine if the second plaintiff, Daniel Love, is accepted as Aboriginal Australian by the the Kamilaroi tribe.

Although the decision has already provoked a furious response from conservative commentators who argue it introduces a new race-based distinction in the constitution, legal experts including Sydney University constitutional law professor, Anne Twomey, have warned it was too soon to know what the possible ramifications for the case might be beyond immigration law.

Wamba Wamba lawyer Eddie Synot, manager of the Indigenous Law Centre at the University of New South Wales, said the judgment concerned a “very narrow application of the aliens power” and explicitly stated it was not a recognition of Aboriginal sovereignty.

“More than anything for me, today just confirmed that the high court is never really going to be an environment where we’re ever going to be able to settle those original questions about sovereignty and the founding of the nations,” Synot said. “It’s going to have to be a political decision outside of the court.”

Synot said the decision had caused some angst among Aboriginal people concerned that a court was yet again appearing to decide on Aboriginal identity and belonging to country. Those concerns have been heightened in recent weeks by a request, swiftly denied, for police to investigate the Aboriginality of author Bruce Pascoe.