Australian deputy prime minister and four senators disqualified from holding office in ruling that could cost government its slender majority

The Australian deputy prime minister, Barnaby Joyce, and four senators have been ruled ineligible to sit in parliament by the high court, with only the National party’s Matt Canavan and NXT’s Nick Xenophon surviving a challenge that has hung over seven parliamentarians since their dual citizenship was discovered in July and August.

The court’s unanimous decision to uphold a strict reading of the constitutional disqualification of foreign citizens will trigger a byelection in the New South Wales seat of New England, won comfortably by Joyce, the National party leader, at the 2016 election. The court’s ruling also forced the deputy National party leader, Fiona Nash, and One Nation’s Malcolm Roberts out of the Senate. Two Greens senators, Scott Ludlam and Larissa Waters, who had already resigned, were confirmed as ineligible by the court.

Joyce’s exit strips Malcolm Turnbull’s government of its one-seat majority in the House of Representatives for now, but he could return through a byelection on 2 December.

At a brief media conference in Canberra on Friday, Turnbull insisted his government still had a majority – it holds 75 of 149 seats in the lower house although one sits in the Speaker’s chair – and enjoyed the support of several crossbench MPs who could guarantee confidence and supply.

“The decision of the court today is clearly not the outcome we were hoping for, but the business of government goes on,” he said. The government would seek to reform the constitution or make other legal changes to “minimise the risk of candidates” being found in breach for holding dual citizenship, Turnbull said.

He thanked Nash for her service, announced he would restore Canavan to cabinet as the minister for resources and northern Australia, and said he himself would take on Joyce’s portfolios of agriculture and water.

The federal president of the Nationals party, Larry Anthony, told the ABC on Friday that the Indigenous affairs minister, Nigel Scullion, will serve as interim leader.

In a joint decision the justices rejected the commonwealth’s argument that MPs or senators would need to have knowledge of their dual citizenship in order to be disqualified.

Speaking after the decision, Joyce, who was born in Australia but held New Zealand citizenship by descent from his father, said he had “no reason to believe that ... I was a citizen of any other country than Australia”.

Joyce said the decision was “tough” but he was not “totally surprised” by it. He said he would not “cry into his beer” but rather prepare for the byelection in New England.

The Labor opposition rounded on the government, with its leader, Bill Shorten, claiming Australia now has “a minority government”:

At a media conference, Labor deputy leader Tanya Plibersek blasted Turnbull’s decision to allow Joyce and Nash to stay in cabinet until the court’s decision and noted the “extraordinary revelation” that Joyce expected he might lose the case.

Plibersek said every decision made by the Joyce and Nash since October 2016 was “under a cloud”, referring to Labor legal advice on a separate section of the constitution that states that a person can hold a ministry for only three months without sitting in parliament.

Plibersek reserved Labor’s options, saying it would “explore” whether to seek a declaration their decisions were invalid.

The court approved of the submissions of the friend of the court and former independent MP Tony Windsor that, except in exceptional circumstances, section 44 of the constitution prohibits citizens or subjects of a foreign power from sitting in parliament.

The justices said this approach adhered most closely to the natural and ordinary meaning of section 44 and the view of the majority in the precedent case of Sykes v Cleary.

Windsor, Joyce’s long-term rival, announced he would not contest New England, but said he might run for the Senate in future, sparing the government a bruising byelection encounter with the former independent.

The court ordered recounts of the votes in the 2016 election to fill vacancies for the senators.

At a media conference the leader of the right-wing One Nation party, Pauline Hanson, said she was “absolutely devastated at losing” Roberts. She announced that Roberts would run in the state seat of Ipswich in the imminent Queensland election. One Nation’s Fraser Anning is likely to replace Roberts after the federal Senate recount.

Former Greens senator Scott Ludlam is likely to be replaced by 22-year old disability advocate Jordon Steele-John, which would make him Australia’s youngest senator.

Andrew Bartlett is likely to replace Waters, although Waters has signalled a desire to return to federal politics.

The Guardian understands that Liberal Hollie Hughes, who held the sixth spot on the New South Wales Senate ticket, will seek to retain Nash’s seat if the recount shows she has won it.

The court accepted Xenophon’s lawyer’s submission that his status as a British overseas citizen did not disqualify him because it lacked core features of citizenship: the ability to enter and reside Britain.

Canavan argued it was “doubtful” that he ever was an Italian citizen, because a 1983 constitutional court decision that Italian citizenship can be passed down through the maternal line might not have been retroactive to his birth in 1980.

The justices noted expert evidence that Canavan might have had to apply for a declaration of Italian citizenship to become a citizen, and said the court could not be satisfied he was Italian.

Waters and Ludlam had already resigned from the Senate, while Xenophon had said he would leave federal politics to contest the South Australian state electionregardless of the court’s decision.

Source: The Guardian