Deputy Prime Minister Barnaby Joyce. Credit:Alex Ellinghausen He told Parliament he had decided to refer himself to the High Court for clarification but would not resign from cabinet and would remain as the member for the NSW electorate of New England. "I was born in Tamworth, just as my mother and my great-grandma was born there 100 years earlier," he said. "Neither I, nor my parents have ever had any reason to believe I may be a citizen of another country. I was born in Australia in 1967 to an Australian mother and think I am fifth-generation. My father was born in New Zealand and came to Australia in 1947 as a British subject. In fact we were all British subjects at that time. "The government has taken legal advice from the Solicitor-General. On the basis of the Solicitor-General's advice, the government is of the firm view that I would not be found to be disqualified by the operation of section 44 of the constitution from serving as the member of New England. However, to provide clarification to this very important area of the law, for this and future parliaments, I have asked the government to refer the matter.

Senators Malcolm Roberts and Matt Canavan, who have both been caught up in questions over dual citizenship. Credit:Alex Ellinghausen "Given the strength of the legal advice the government has received, the Prime Minister has asked that I remain as Deputy Prime Minister and continue my ministerial duties." But experts believe Mr Joyce could well be a dual citizen, forcing a byelection for his seat and putting the Turnbull government's slim majority at risk. Under New Zealand law anyone born overseas to a NZ father between 1949 and 1978 is considered a "citizen by descent". Labor called for Mr Joyce to stand aside while the matter is being considered by the High Court, citing Senator Canavan's case.

"How on earth could this Parliament be claiming to have a majority government, relying on the vote of someone they don't know whether or not he has been lawfully elected?" manager of opposition business Tony Burke said. "How on earth can this government have someone in the office of Deputy Prime Minister, when they don't even know if he is meant to be a member of Parliament? "And if the minister for resources was able to stand aside, even though he has the Attorney-General beside him, claiming that he had a strong case, then why on earth is strong case the defence for the Deputy Prime Minister? "How on earth does that work?" Born in Tamworth

Mr Joyce's father James Michael Joyce was born in the NZ city of Dunedin in January 1924, according to Australian Securities and Investment Commission company records. He moved to Sydney to attend university, later married and settled in NSW. Barnaby Joyce was born in Tamworth in 1967. Mr Joyce has not been through any formal renunciation process and his office cannot say whether his father - now in his 90s - ever renounced. While the older Mr Joyce was born a British subject, it's believed he became a NZ citizen with the passage of a 1948 citizenship law. Crucially, experts say NZ law - section 7 of the British Nationality and New Zealand Citizenship Act - confers citizenship by descent automatically, and does not need to be activated. While there is a process for registering NZ citizenship by descent to attain a passport, University of Auckland international law expert Anna Hood believes that may not matter. "If Barnaby's father was indeed a New Zealand citizen in 1967 then it looks like Barnaby may have become a New Zealand citizen at birth courtesy of section 7 of the 1948 Act," Dr Hood told Fairfax Media.

"There is a question about whether Barnaby or his parents would have had to register him as a New Zealand citizen. However, section 7 of the 1948 act does not explicitly require individuals born to New Zealand fathers to register their citizenship." Dr Hood also points to another section of the act, which provides that every person born outside NZ between January 1, 1949, and January 1, 1978, shall be a New Zealand citizen by descent if born to a Kiwi father. My Joyce's spokesman has previously said the MP had independently established he was not a dual citizen "many years prior to entering Parliament". However his office has not elaborated on what steps he took. Deputy PM 'shocked' Fairfax Media sent emails to New Zealand's citizenship office, the Internal Affairs department, last Wednesday, asking for clarification over the nation's citizenship laws.

Mr Joyce told Parliament he was contacted the next day. "Last Thursday afternoon, the New Zealand high commission contacted me to advise that on the basis of preliminary advice from the Department of Internal Affairs which had received inquiries, considered that I could be a citizen of New Zealand by descent," Mr Joyce said. "Needless to say, I was shocked about this." Before Mr Joyce's statement, Fairfax Media followed up with Internal Affairs, asking again for a response to last week's questions. Despite having advised the New Zealand high commission there may be an issue, a spokesman from the New Zealand department said it had "not yet received a response from the relevant experts".

'Everyone had conversations' University of NSW constitutional law expert George Williams said Mr Joyce could be "in some difficulty". "The only question here is, 'Is he regarded under New Zealand law as a citizen?' That's not a question of activation - in fact this can happen without a person's knowledge or consent," Professor Williams said. "It doesn't even have to be registered, it's just, 'Is he entitled to the benefits under their law should he wish to take them up?' It doesn't matter if he has. If he has that entitlement, that is what the constitution extends to." Mr Joyce has been asked several times if he is a dual citizen, following the shock resignations of Greens senators Scott Ludlam and Larissa Waters last month.

Two weeks ago, Mr Joyce joked on Today that "everyone has had their conversation with their mothers and fathers" that they weren't made citizens of Botswana while they were sleeping. "I was born in Tamworth Base Hospital, where my great-grandmother was born 100 years before me and I am an Australian, no problems there." It was only after Fairfax Media investigated NZ law, pressing Mr Joyce's office on the issue, that they began to take the matter seriously. Similar to Canavan case Anne Twomey from the University of Sydney believed Mr Joyce's case resembles that of Senator Canavan, who was apparently given Italian citizenship by descent after his mother made an application on his behalf. The High Court judgment on the case of Senator Canavan - who has stood down from the ministry but remains in the upper house - could affect Mr Joyce.

"The fact that another country can have these rules about citizenship by descent, which people have not the foggiest idea about, is potentially problematic. It may be that the High Court tries to wind these things back - so if you were born in Australia, and you haven't taken any steps to gain any foreign citizenship, then maybe that is enough to avoid disqualification," she said. "We need to know whether the mere fact that you are descended from someone and that gives you the right to do something in relation to foreign citizenship - like obtaining a passport - is sufficient to trigger this or not? I am sure many politicians would like to know that." Senator Canavan was forced to step down after it was revealed his mother had applied for Italian citizenship on his behalf, when he was 25. But he is asking the High Court to rule whether he is still eligible to stand in Parliament, as he was unaware his mother had taken this step. When Senator Canavan stepped down from the cabinet, Mr Joyce took on his ministerial responsibilities.

The High Court considers whether an MP took all reasonable steps to renounce their citizenship before nominating for election to Parliament. Mr Joyce, who is not registered with New Zealand authorities as a citizen, is expected to argue he had no way of knowing he was a dual citizen, having previously inquired to see if he was registered with NZ authorities, and receiving a "no". Kiwi by descent On its official website, the New Zealand Department of Internal Affairs notes: "If you were born overseas and at least one of your parents is a New Zealand citizen by birth or grant, you are an New Zealand citizen by descent." In separate education material, the department says: "Like a citizen by birth, a New Zealand citizen by descent acquires his or her citizenship status automatically at the time of his or her birth. However many people choose to register their citizenship by descent status with the Citizenship Office of the Department of Internal Affairs in order to obtain a certificate to prove they are a New Zealand citizen."

And in a 2015 press release, the department said: "Babies born in Australia and other countries to New Zealand parents are still Kiwis. Before an overseas-based family brings their new baby home to meet the Kiwi cousins, they need to register him/her as a citizen by descent before they can apply for a New Zealand passport." The registration process involves filling out a form labelled "Confirmation of New Zealand Citizenship By Descent", rather than calling it an application for citizenship. The registration process costs $NZ204.40 ($189). Former independent MP Tony Windsor, who challenged Mr Joyce for his seat of New England at the 2016 election, wouldn't rule out another attempt if the citizenship fiasco triggered a byelection. "It's not front of mind but you never rule anything out in life," Mr Windsor, a long-time foe of the Nationals leader, told Fairfax Media.



"If he's ruled out, it's a whole new ball game." 'Opportunity' for other MPs

Prime Minister Malcolm Turnbull wrote to Opposition Leader Bill Shorten on Monday, advising him of Mr Joyce's referral to the High Court, and offered him the "opportunity" to refer any Labor MPs who may potentially fall foul of the same constitutional section. "It is manifestly in the national interest that the High Court have the opportunity to clarify the limits on the operation of section 44 of the constitution," Mr Turnbull wrote. "With around half of all Australians having a foreign born parent, and with many foreign nations having citizenship laws which confer citizenship by descent, regardless of place of birth, the potential for many, possibly millions of Australians unknowingly having dual citizenship is considerable. "I am writing to you to offer you the opportunity to nominate any Labor members or senators whose circumstances may raise questions under section 44 of the constitution so that the Parliament can also refer these matters to the High Court for its consideration. "The Australian people must have confidence in our political system and resolving any uncertainty is vital."

Loading Mr Turnbull said the legal advice sought by the government left it "satisfied that the court would not find Mr Joyce disqualified to sit in the House". Follow us on Facebook