14/08/2017 10:24 AM AEST | Updated 14/08/2017 12:16 PM AEST

Barnaby Joyce May Be A New Zealand Citizen

His father was born in New Zealand.

CANBERRA -- The second most senior politician in Australia is the latest to be caught up in the parliamentary citizenship scandal which has claimed the scalps of several senators and possibly several more.

Deputy Prime Minister and Nationals leader Barnaby Joyce has announced to parliament that the New Zealand High Commission informed him last Thursday, based on preliminary advice, that he may be a New Zealand citizen by reason of descent and he has now referred himself to the High Court.

If Joyce is a dual citizen he could be in breach of Section 44 of the Australian Constitution, making him ineligible to hold a seat in the House of Representatives. The Turnbull Government holds power with a paper thin one seat majority in the lower house.

"Needless to say, I was shocked about this," Joyce told parliament. "I've always been an Australian citizen born in Tamworth. Neither my or my parents had any reason to believe that I may be a citizen of any other country.

"I was born in Australia in 1967 to an Australian mother and I think I'm fifth generation. My father was born in New Zealand, came to Australia in 1947 as a British subject. In fact, we were all British subjects at this time."

The Greens Larissa Waters and Scott Ludlam have resigned over dual citizenship, while Nationals senator Matt Canavan has stepped down from Cabinet and ministerial roles, but not resigned from the Senate, while his case is determined.

One Nation senator Malcolm Roberts has had a cloud over his citizenship and has been referred to the High Court. He hasn't helped his case by considerably shifting the explanation of his situation over the past few weeks.

When the Greens cases emerged, Prime Minister Malcolm Turnbull was quick to lambast the party for "extraordinary negligence" for allowing two senators to serve while ineligible. On Monday, Turnbull offered Opposition Leader Bill Shorten the "opportunity" to refer to the High Court any Labor MPs who may potentially have the same problems with the same section of the Constitution.

He said it is "manifestly in the national interest" that the High Court "clarifies the limits" of Section 44(i) of the Constitution.

"The Australian people must have confidence in our political system and resolving any uncertainty is vital," the Prime Minister wrote.

Citizenship rules in NZ state that if a parent is a NZ citizen at the time of a child's birth, then that child also holds NZ citizenship by descent. A person does not have to register the citizenship, it comes automatically at birth.

"The concept of New Zealand-Australian citizenship was not created until 1948," Joyce said.

"Neither my parents nor I had ever applied to register me as a New Zealand citizen. The New Zealand Government has no record of registering me as a New Zealand citizen."

Joyce cited legal advice from the Solicitor General that he has not breached the Constitution, but he has referred the matter to the High Court for determination.

He'll remain Deputy Prime Minister and is already covering the portfolios of Senator Canavan while his own dual citizenship status is sorted out by the High Court.

Labor's Anthony Albanese said it's for the Turnbull Government to decide whether Joyce should remain in his portfolios at this time or stand down.