Labor frontbencher Tony Burke has predicted a "very large" round of referrals to the High Court over the worsening dual citizenship fiasco, with up to 13 MPs at risk of becoming fresh casualties.
While Mr Burke promised to refer embattled Labor MP David Feeney if he can't stump up the relevant documents, Attorney-General George Brandis said all opposition MPs in doubt must face the court to preserve the integrity of Parliament.
The fresh doubts raised following the finalisation of the Parliament's citizenship disclosure process on Tuesday could lead to a series of byelections in early 2018, including Mr Feeney's electorate of Batman, which could fall to the Greens.
Labor has remained largely unscathed in the citizenship fiasco, but the cases of lower house MPs Josh Wilson, Justine Keay, Anne Aly and Susan Lamb are now under intense scrutiny. Each Labor MP appears to have tried to renounce their citizenship prior to the 2016 election, but failed to receive confirmation until after the close of nominations.
"I think what we're in now is a situation where there will be a very large number of referrals to the High Court," Mr Burke said. "What we can have at the end of all of this is a situation where either the government uses its numbers for hostile referrals or where the public still have question marks and the High Court don't get to deal with all the relevant issues."
But on Wednesday morning, Labor senator Katy Gallagher - whose renunciation was not confirmed until after the election - stood down from her frontbench roles and said she had "formed the view" she should be considered by the High Court.
"I have previously stated that I do not think there is a basis to refer my eligibility to the High Court for determination. I stand by that position. I have also said that the referral would ultimately be a matter for the Senate, I stand by that position too," Senator Gallagher said.
"It is however clear to me that the government has decided that I should be referred, despite having full access to all of my legal advice and expert reports for the past two days."
Government ministers have dismissed Mr Burke's arguments and said the renunciation must have taken affect before the close of nominations.
Senator Brandis said the Labor cases must face the court's scrutiny.
"What we hope will happen is that [Opposition Leader Bill Shorten] will do the right thing and refer them himself," Senator Brandis said.
Asked if the government would refer the MPs to court if Labor didn't, Senator Brandis said: "We will have to because the House of Representatives has an obligation to protect the integrity of its own chamber."
Labor's legal affairs spokesman Mark Dreyfus dismissed the danger to MPs on his side, zeroing in on Liberals, including Environment and Energy Minister Josh Frydenberg, whose Jewish mother fled the Nazis and arrived in Australia stateless.
"It's a matter of the constitution of Australia. I'm simply making the point that the High Court decisions need to be applied, the constitution needs to be observed. The High Court has said it is a matter of foreign law, foreign citizenship law," he said.
Mr Dreyfus has attacked Mr Frydenberg for not lodging any paperwork to prove he is not a dual citizen, despite not lodging any citizenship documents in his own disclosure.
Mr Dreyfus, whose Jewish father and grandparents fled Nazi Germany, said his case was different and he didn't need to provide legal advice to the Parliament.
"I don't need legal advice because I know what the law was in Germany during the war, and I know what the law is after the war in Germany. I do after all have some legal qualifications. And it's very clear to me what happened in the case of my family," he said.
Other Liberals potentially facing difficulty include Jason Falinski, Ross Vasta, Nola Marino, Julia Banks, Alex Hawke, Arthur Sinodinos and Michael McCormack. The Nick Xenophon Team's Rebekha Sharkie is also in doubt.