Why Australian MPs are heading for the high court over dual citizenship – explainer

What is this high court case about?

The high court is to rule on whether a clutch of senators and members of the House of Representatives should be turfed out because they were dual citizens when they were elected last July.

Section 44 of the Australian constitution says that any person who is a “citizen of a foreign power” is “incapable of being chosen or of sitting as a senator or a member of the House of Representatives”.

The court is deciding whether these parliamentarians were eligible to take their seats in the first place.

This first hearing is in Brisbane – why not Canberra?

Because the air conditioning system in Canberra’s high court building is 37 years old and is getting a makeover. Next month will be Melbourne, with Canberra back online in October.

Who is in the frame for this hearing?

Five people who all say they unwittingly held dual citizenship, either based on where they were born or by descent (through parents or grandparents), have been referred.

Three of them are or were Queensland senators: Larissa Waters (Greens), who was born in Canada; Matthew Canavan (Liberal National party), who became an Italian citizen when his mother applied for him on the back of her lineage; and Malcolm Roberts, who held British citizenship after being born in India to a Welsh father.

Then there’s Scott Ludlam, the former Greens senator for Western Australia, who was born in New Zealand, and the deputy prime minister, Barnaby Joyce, who was born in Australia to a New Zealand father.

Anyone else?

The high court is awaiting two more referrals from parliament next month. They relate to the New South Wales senator and deputy Nationals leader, Fiona Nash, who was British via her Scottish father, and the South Australian senator Nick Xenophon, who was British via his father, who is from the former British colony of Cyprus. Nash and Xenophon may well be lumped in with the case of the five others.

What if more of these dual citizens keep cropping up?

Each further individual case will have to be referred to the court, as the rulings will turn on their particular circumstances, constitutional experts and lawyers say. The more cases, the longer in turn it could take for these proceedings to clear up this cloud hanging over federal parliament.

“One of the hard things about this particular issue is we’re seeing this drip-feeding of eligibility questions coming out,” says Lorraine Finlay, a constitutional law expert from Murdoch University, who supports a parliament-wide audit of citizenship status.

“And what we actually need to happen is have a line drawn in the sand, and deal with all of the questions there and move on. At the moment it’s really hard to see that happening.”

Bill Shorten, the Labor leader, whose father was born in the north of England, says he renounced British citizenship in 2006 but has so far resisted showing documentary proof. He has told Malcolm Turnbull to produce evidence to the contrary or stop pursuing him on the issue, likening it to the Barack Obama “birther” accusations.

How long will this take to resolve?

A few months at least. The attorney general, George Brandis, suggests the court may be able to hand down rulings in October, which Finlay says seems right. Her fellow expert George Williams, from the University of New South Wales, says this “would seem to be optimistic”.

“I think you would expect them to be resolved by Christmas,” he says.

This means the Senate vacancies in Western Australia and Queensland left by Ludlam and Waters , who quit on learning they were dual citizens, may not be filled for four months.

Didn’t Ludlam and Waters do the decent thing?

Ludlam said he did not know he was a New Zealand citizen but that he should have checked and that it was an “avoidable oversight”. Waters, who was born in Canada to Australian parents, said much the same. Theirs were the first cases to break and at the time much of the media attention characterised the Greens’ party processes as a shambles.

Since then the political situation has become more complicated.

Canavan, from the National party, said he had no knowledge and stood down from cabinet but did not quit parliament. Joyce, his party leader, stayed in the cabinet.

In a submission to the high court on Monday, the attorney general, George Brandis, accepted that Canavan and Joyce were citizens of Italy and New Zealand respectively.

Roberts insists that he had renounced his British citizenship by the time he was elected to the Senate in 2016, but his party leader, Pauline Hanson, referred his case to the high court anyway to achieve a final resolution. He has stayed in the Senate.

The Greens joint deputy leaders have subsequently received some credit for their stance. But Williams argues that the high court could effectively determine that their resignations were “a futile and unnecessary” act. “If it turns out they’re not disqualified, then actually quitting is most unfortunate because they’re entitled to retain their seat in parliament.”

Waters’ Canadian citizenship was officially annulled on 5 August and she wants to contest her Senate seat at the next election. Ludlam’s not sure what he will do.

If anyone is ineligible, does that mean their votes in parliament were illegitimate? Should dual citizens not cast their vote in case the court rules against them?

There’s no obligation to withhold their votes or not participate in parliament until the court rules on their eligibility, according to Finlay.

“And the high court has further said that once you are declared ineligible, any votes that you’ve participated in are still valid votes, so it’s not as though you look backwards and undo all the work that happened.”

The constitution looks clear – dual citizens get turfed. Aren’t these open-and-shut cases?

Not so, say the experts.

The high court has previously found a literal reading of section 44 would be absurd, since a foreign country could mess with Australian parliamentarians simply by changing their laws, according to Finlay. In the Sykes v Cleary case of 1992, the court, reading between the lines of the constitution, ruled that if an MP took all reasonable steps to renounce foreign citizenship, that was good enough.

What’s new in these cases is the question of whether people who did not know they were dual citizens should have known. Is ignorance an excuse?

“It may be they say, if you are [a dual citizen] you are, and there’s no reasonableness requirement at all,” Finlay says. “Or it might be they say if you were born overseas or even if your parent was overseas, it’s reasonable for you to turn your mind to the question.”

Williams says the court may or may not apply a “reasonableness test” but “we are getting into unknown territory because the high court has just not ruled on these matters yet”.

Will the rulings all go one way?

Not necessarily, as the court will apply its interpretation of the law to “the particular facts” in each case “and that’s why you may find some are disqualified and some are not”, Williams says.

Roberts’ case differs from the others in that he has said that before nominating for the Senate, he emailed British authorities to say he didn’t believe he was a British citizen but renounced this in any case.

Graeme Orr, from the University of Queensland, says an interesting question arises because there are no opposing or “adversarial” sides in this case. How much will each parliamentarian’s account of how much they knew of their circumstances be tested?

Finlay says it would be “extraordinary” for the court to step up any active contesting of evidence.

“They do have the capacity to call for witnesses but that is very rare,” she says. Most often the court will require documentary proof such as sworn statements and citizenship application papers.

Williams says the amount of testing of evidence was likely to vary widely from case to case. “The Barnaby Joyce case, there wouldn’t be contested evidence, that’s pretty straightforward, the Matt Canavan one less so.”

Will Queensland and WA have to wait till the end of this case to get its replacement senators for Ludlam and Waters?

“That’s guaranteed,” Finlay says. Whether or not the Greens senators were validly elected determines how they will be replaced, so the court’s decision on the question of the unwitting dual citizen in parliament will have to come down first.

If disqualified, it will go to a recount, with the next contenders – in WA, Jordon Steele-John, and in Queensland, Andrew Bartlett – likely to get the nod.

But if Waters and Ludlam were validly elected and quit prematurely, each could theoretically get a second bite of the cherry by nominating to fill the casual vacancies they left themselves.

What will happen in the first hearing?

Not an awful lot. But directions hearings usually set the timelines of the case, outlining “who has to provide what and when”, Finlay says. She says the court might also hear mention of Nash and Xenophon looming as a future part of the case, which could push the timeline back further.

Barristers may or may not air some broad sketches of how they intend to press the parliamentarians’ cases as “the court may have a wish to have an indication of what areas they’ll be covering in submissions”, Williams says.

Was this always going to end up in the high court? Was there any other way to resolve this?

The high court, as “the final arbiter of these things and particularly when there’s such doubt about these matters”, is absolutely the forum to resolve the dual citizen imbroglio, Williams says.

Finlay agrees, even though the constitution doesn’t require parliament to refer these cases to the high court. “Constitutionally the way this has played out means the high court has to rule on it. What we’re struggling with here is confidence in the institution of parliament because of the sheer number of cases. Parliament could have taken it into their own hands if they wanted to do.

“But the fact is if they had done that, I think the Australian people would have looked upon that with a lot of scepticism. It is much better in these cases to have it looked at by the independent umpire rather than having the very people whose eligibility is under question making the decision themselves.”

Orr has a dissenting opinion. He more or less says that parliament could sort out the dual citizen debacle by itself without tying up the court: do an audit of all its members, declare an amnesty for all unwitting dual citizens to renounce, and get on with it.

He says the assumption is that “everything has to be referred to the high court” when disqualification questions arise, but that parliament “in the stroke of a pen” could return to “what I think was the clear original intention of the constitution and the Electoral Act”.

“This is that elections are never perfect, you have 40 days to challenge them, and after that parliament has to get on with its business,” he says. “And after that if any disqualification issues arise, it’s really a matter for the future – does this MP fix it up or do they get kicked out of parliament? That would be the rational way to do it for any sensible organisation that’s worried about resolving a problem and not worrying about its brand.

“But parliament is not rational in that sense. It’s a political, partisan, media-driven maelstrom.”