More federal MPs could face High Court scrutiny as they put their citizenship cards on the table.
Senators produced their family history and citizenship documents on Monday, following the fiasco which has claimed the scalps of eight colleagues so far.
House of Representatives members have until 9am to put in their documentation, followed by their publication on the parliamentary website later in the day.
The government is weighing up whether to seek the Senate's support to refer opposition frontbencher Katy Gallagher to the court, who could be the first Labor member to face scrutiny.
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.
Under section 44 of the constitution, dual citizens are ineligible to sit in parliament.
According to paperwork she lodged under new parliamentary rules for citizenship disclosure, Senator Gallagher completed a British citizenship renunciation form, with payment, on April 20, 2016.
But the UK Home Office wrote back on July 1, almost a month after election nominations closed, requesting original copies of her birth certificate and parents' marriage certificate.
Senator Gallagher, whose father was born in the UK in 1939, did not receive the formal renunciation document until August 16, just over two months past the nomination date for the election.
She has legal advice which says she took all of the steps required of her under British law to renounce her UK citizenship.
Based on this advice, she sees no reason to refer herself to the High Court.
Labor is unlikely to support a referral, however the government could get the numbers with the support of the Greens and one crossbencher.
The Greens will discuss the referral at a party room meeting on Tuesday.
Labor MPs Susan Lamb and Justine Keay and crossbencher Rebekha Sharkie have also been in the government's sights.