Malcolm Turnbull has launched a passionate defence of minister Josh Frydenberg, saying it's absurd to claim he's inherited Hungarian citizenship from his mother who was stateless when she fled the country "which would have pushed them into the gas chambers."
The prime minister accused those pushing for a citizenship audit of MPs as engaging in "witch hunts", also taking aim at critics of the energy minister who have questioned his citizenship.
"Has this witch-hunt become so absurd that people are seriously claiming that Josh Frydenberg is the citizen of a country which has stripped his mother and her family of their citizenship and would have pushed them into the gas chambers had it not been that the war was ended before they had time to do so?" Mr Turnbull asked reporters in Perth on Friday.
He said politicians should not be tried by "innuendo and smear", but rather any parliamentarian was able to stand up, offer evidence and move to refer one of their colleagues to the High Court, the only body with the power to disqualify MPs.
The prime minister's defence came as Labor leader Bill Shorten announced his party was prepared to cooperate with the government on "an agreed process that brings this issue to an end".
"Whatever the ultimate process is, it must adhere to clear principles," Mr Shorten said in a statement.
"It must be accountable to the people through the parliament. It must have bipartisan agreement prior to implementation. It must be sufficiently robust to give all Australians confidence in the process.
"But it must not be allowed to create more legal problems, or in any way undermine the supremacy of the High Court on these matters."
Mr Frydenberg's mother was born in Hungary in 1943 and arrived in Australia "stateless" with her parents when she was seven after spending time in a refugee camp.
"It is absurd to think that I could involuntarily acquire citizenship of a foreign country from a stateless mother and grandparents," Mr Frydenberg told AAP on Friday.
Two of Mr Frydenberg's ministerial colleagues Barnaby Joyce and Fiona Nash were disqualified from parliament by the High Court over their dual citizenship-by-descent last Friday.
The Australian newspaper reported on Friday that Hungary has rules that can confer citizenship by descent.
Attorney-General George Brandis said rather than an audit, he expected a parliamentary committee would come up with proposals to either change section 44 of the constitution through a referendum or find a legislative means of sorting out the problem.
He said the Labor and Liberal parties had exhaustive processes for candidates to declare and prove their eligibility.
Conservative Liberal MP Kevin Andrews is among those pushing for an audit, insisting it was time to lance the "festering sore".
"This has now become a festering sore for the government. We can't talk about anything else. We need to get this resolved," Mr Andrews told ABC TV.
Communications Minister Mitch Fifield revealed on Thursday now-resigned Senate President Stephen Parry had confessed to him in August about possibly being a dual UK-Australian citizen, but did not take action until this week.
Mr Turnbull said he was not aware of the conversation, but it had been Mr Parry's responsibility to comply with the constitution.
