Australian Deputy PM Barnaby Joyce renounces NZ citizenship

Australian Deputy Prime Minister 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 on Tuesday.

"We're looking forward to the written advice turning up pronto."

The citizenship dilemma has caused a trans-Tasman political brawl, with Australia's Foreign Minister Julie Bishop accusing the New Zealand Labour party of conspiring to bring down her government.

Mr Joyce is the third Australian member of parliament to discover they actually hold dual citizenship, which is against their parliamentary rules.

Mr Joyce had referred himself to the High Court over the matter, which could have forced him to resign.

Ms Bishop had threatened Jacinda Ardern's Labour party in an omonious message, saying: "New Zealand's facing an election. Should there be a change of government, I'd find it very hard to build trust with those involved in allegations designed to undermine the government of Australia."

Labour MP Chris Hipkins had done some digging for a mate in the Australia, looking for information which could bring down Mr Joyce - and potentially, Prime Minister Malcolm Turnbull's entire government.

Mr Joyce's position in Australia's Parliament was under threat because of a quirk in the law which means despite being born there, he is a New Zealand citizen through his father.

Last Wednesday, Mr Hipkins asked this very specific question of the Minister of Internal Affairs: "Would a child born in Australia to a New Zealand father automatically have New Zealand citizenship?"

It was what's called a written question and a response was due back in six working days.

But Australian journalists were making inquiries of their own at the same time and had already gone to the Department of Internal Affairs themselves.

The story broke on Monday, before Mr Hipkins' answers had come back.

Ms Bishop slammed the question as "highly unethical".

It is a tribal Trans-Tasman fight. Mr Joyce is leader of the National party, which is in coalition with Malcolm Turnbull's centre-right Liberal party.

Ms Bishop is one of its senior members and took the fight to Australian Labor leader Bill Shorten.

"The New Zealand Labour leader has confirmed that a Labour member was contacted by a member of the Labour party here, Bill Shorten must reveal the name of that member," she said.

But Minister of Internal Affairs Peter Dunne says the official information about Mr Joyce's citizenship was given to the Australian journalists.

NZN / Newshub.