Hopes parliament's citizenship fiasco could be swiftly brought to an end are fading with more than a dozen federal politicians potentially facing referrals to the High Court.
Behind the scenes, horse trading is underway between the major parties as the contents of 226 sets of disclosure documents tabled in parliament are digested.
Labor's hit list on the government benches includes Jason Falinski, Ross Vasta, Nola Marino, Julia Banks, Alex Hawke, Michael McCormack and potentially cabinet minister Josh Frydenberg and Senator Arthur Sinodinos.
The Turnbull government is gunning for David Feeney, Justine Keay, Susan Lamb and Josh Wilson as well as Katy Gallagher in the Senate.
Nick Xenophon Team MP Rebekha Sharkie's eligibility is also in doubt.
Mr Feeney says he will be asking to be referred to the High Court on Thursday if documents relating to his UK citizenship renunciation can't be found in time, potentially triggering a by-election in his Victorian seat of Batman.
He famously forgot to declare a $2.3 million investment property in Melbourne last year.
Shadow Attorney-General Mark Dreyfus defended Mr Feeney's sloppiness on Tuesday night, while insisting the coalition could be a "constitutionally illegitimate government".
"We've seen a continuing cover-up out of a system that was meant to provide disclosure," Mr Dreyfus told reporters, adding referrals to the High Court shouldn't be made on a tit-for-tat basis.
Cabinet minister Christopher Pyne hit back, seizing on the four Labor MPs "London to a brick heading for by-elections".
"Bill Shorten has been harbouring these people for the last six months," Mr Pyne told 6PR Perth Radio.
Mr Falinski has sought further legal advice after being unable to ascertain whether his USSR-born father, Polish and British born grandfathers and Leningrad-born grandmother conferred foreign citizenship on him.
Mr Vasta's declaration did not provide evidence he renounced his Italian citizenship in 2001.
Ms Keay, whose father was born in the UK, received confirmation she had renounced her citizenship on July 8, 2016, six days after election day.
Ms Lamb, whose father was born in Scotland, filled out her renunciation form on May 24, 2016.
However, on August 10, 2016, the British bureaucracy told her: "We cannot be satisfied from the documents available that you hold British citizenship. The application has therefore been refused."
Mr Wilson, who was born in London, completed his renunciation form on May 12, 2016.
However, the date of the UK Home Office letter confirming renunciation was June 24, well after the close of nominations for the 2016 election.
Ms Sharkie renounced her British ties on April 19, last year, but did not get confirmation until June 29, after nominations closed.
Senator Gallagher, the former ACT chief minister, did not receive confirmation of her UK citizenship renunciation until two months after nominations closed for the 2016 federal election and 118 days after she lodged the application.
Former senators Jacqui Lambie and Skye Kakoschke-Moore, and former Senate President Stephen Parry, already have dates with the High Court.