Barnaby Joyce has told parliament he is no longer a New Zealand citizen after completing the renunciation process at the weekend.
"We've received verbal communication from New Zealand before question time that that has now been accepted," the deputy prime minister said today.
It came during a fiery question time in Canberra, with Prime Minister Malcolm Turnbull taking aim at Labor leader Bill Shorten for his alleged attempts to undermine the government with the help of the Labour Party in New Zealand.
Earlier today, New Zealand Labour leader Jacinda Ardern hit back at claims of collusion between the two parties in relation to unearthing Mr Joyce's citizenship status.
Foreign Minister Julie Bishop told reporters in Canberra this morning that it would be "very difficult to build trust" with a Labour government should the opposition party win the upcoming New Zealand election.
The citizenship crisis was sparked by yesterday's bombshell announcement from Mr Joyce that he may have technically been a New Zealand resident.
He was referred to the High Court to test whether his New Zealand citizenship-by-descent makes him ineligible to sit in parliament.
Mr Joyce revealed in parliament yesterday he had been advised by the New Zealand high commission he could be a New Zealander as his father was born there.
The revelations put the Liberal party in danger of losing its one-seat majority if Mr Joyce is disqualified from parliament.
Ms Ardern said any suggestion of a conspiracy was "false" and she knew "absolutely nothing" about the Barnaby Joyce case until it broke in the media on Monday.
"I greatly value New Zealand's relationship with the Australian government. I will not let false claims stand in the way of that relationship," she said.
Having criticised the Australian Labor Party over an incident involving contact with an NZ Labour MP, Ms Bishop was asked whether she would trust a future NZ Labour government.
"I would find it very difficult to build trust with members of a political party that had been used by the Australian Labor Party to seek to undermine the Australian government," Ms Bishop said.
Ms Bishop said Labor leader Bill Shorten "sought to use a foreign political party to raise a serious allegation in a foreign parliament designed to undermine confidence in the Australian government.
"Bill Shorten must reveal who he put up to this dirty tactic and the details of this urging of a foreign political party to be in involved," she said.
Conservative independent MP Bob Katter said the Turnbull government could not rely on his support should it slip into minority.
If the High Court rules Deputy Prime Minister Barnaby Joyce ineligible to sit and he loses a by-election in his safe New England seat, the government would need the support of one of five crossbenchers to survive.
"It's back to the drawing board," Mr Katter said, when asked today about guaranteeing confidence and supply.
Another independent MP Andrew Wilkie said he would continue to approach all issues in the parliament on their merits and has "not guaranteed anyone anything".
Nick Xenophon Team MP Rebekha Sharkie said Mr Joyce should step aside from cabinet while the court determines his eligibility.
But she said any suggestion of the government needing crossbench support was a "long, long way away".
"What I want to see is ... a stable government," she told Sky News. "I won't be supporting party games but I do think we could have some greater certainty around cabinet."
Comment was being sought from independent Cathy McGowan and Greens MP Adam Bandt.
Attorney-General George Brandis told TODAY this morning that anyone who doubted Barnaby Joyce as an Australian was “completely absurd”.
“I think most Australians would think that the idea that Barnaby Joyce is anything other than a dinky-di Aussie is completely absurd,” he told TODAY Show co-host Lisa Wilkinson this morning.
Mr Brandis said the information about Mr Joyce’s New Zealand citizenship came about as a result of “skulduggery contrived by the Australian Labor party with the New Zealand Labor party”.
“Mr Joyce had absolutely no reason to think that the operation of New Zealand’s citizenship law would apply to him,” he said.
Labor says Malcolm Turnbull must explain why one minister - LNP Senator Matthew Canavan - has stood aside over citizenship issues while Mr Joyce remains in the cabinet.
Mr Canavan stepped aside last month when he discovered he is an Italian citizen.
“They need to release the advice as to why the situation for Senator Canavan is different to the situation for the member for New England (Mr Joyce),” Labor MP Tony Burke said in parliament yesterday.
“The facts of Senator Canavan’s case, and the legal issues concerning Italian laws… are completely different from the facts and legal issues of Mr Joyce’s case,” he said.
“For a start because they involve the interpretation of Italian law which is a matter of some complexity.”
He said the government is acting on senator general advice for both cases.
New Zealand prime minister Bill English told reporters he had been advised Mr Joyce was a New Zealand citizen by descent, but it was up to the Australian courts to determine whether this affected the Nationals leader's parliamentary role.
Labor leader Bill Shorten used question time to pressure the prime minister over his reluctance to stand Mr Joyce aside, and is expected to ramp up the attack today.
Mr Turnbull said Mr Joyce was qualified to sit in parliament and the High Court would find in favour of him.
He also hit back at Labor’s hard line, threatening to refer five of its MPs to the High Court to force them to prove they’ve renounced foreign citizenship, embroiling more people in the scandal.