Prime Minister Malcolm Turnbull and the Greens both stand to benefit from the worsening fiasco if the four Labor MPs with questions over their eligibility are referred to the High Court.
The citizenship crisis has engulfed another nine parliamentarians, following yesterday's citizenship audit of all MPs..
Labor tried to pass a motion that referred nine MPs to the High Court, but that was narrowly voted down on Wednesday night in the House of Representatives.
TOP IMAGE: Last year David Feeney beat Greens candidate Alex Bhathal for the Victorian seat of Batman by a whisker.
"They've got people who are dual citizens, so they think if the House is going to refer them to the High Court, it should also refer some of ours who are not dual citizens".
"The government does expect that Mr Shorten will take the step that has been taken by the Leader of the Opposition in the Senate, and refer those four members to the Court of Disputed Returns because if he fails to do so, that raises very serious questions about Bill Shorten's own credibility", Senator Brandis told the upper house after Senator Gallagher's statement.
'As far as I am aware, those documents were sent to the relevant British and Irish authorities as required at the time, ' he wrote in a declaration.
If Senator Gallagher is disqualified it could set in train a super Saturday of by-elections for the Labor lower house MPs, Justine Keay, Susan Lamb and Josh Wilson.
Senator Gallagher, whose father was born in the United Kingdom in 1939, did not receive the formal renunciation document until August 16, just over two months past the nomination date for the election.
Australia Post confirmed the form was delivered to the UK Home Office on May 23.
He said he still had inquiries outstanding with the UK, and had also sought past bank records to determine whether he had made a payment that was processed by the UK Home Office at the time.
Senator Gallagher believes that she does not have a case to answer but chose to refer herself after political attacks continued despite her contention that she had taken all reasonable attempts to renounce her British citizenship by descent.
They will argue they took "all reasonable steps" to renounce their dual citizenship, but none received confirmation their applications were successful before the June 9, 2016 deadline.
The Liberal MP may be a dual citizen by descent through his USSR-born father, his Polish and British born grandfathers or his Leningrad-born grandmother.
In his disclosure, Mr Falinski stated he had never held citizenship of another nation, but provided no evidence to support this, saying only that he had sought legal advice "to confirm my citizenship status exclusively as an Australian citizen".
It would have referred four of Labor's own MPs, four Coalition MPs and the Nick Xenophon Team MP Rebekha Sharkie, who also supported the motion.
This could mean they not in the clear, as Mr Turnbull gave his MPs weeks to prepare the needed documents, The Sydney Morning Herald reported.
On Wednesday morning Gallagher announced to the Senate that she had asked for her eligibility to be referred to the High Court.
Gallagher, a former ACT Chief Minister, did not receive confirmation of her United Kingdom citizenship renunciation until two months after nominations closed for the 2016 federal election - 118 days after she lodged the application.
But the UK Home Office wrote back on July 1, nearly a month after election nominations closed, requesting original copies of her birth certificate and parents' marriage certificate.
Attorney-General George Brandis told parliament the government did not reflect on the integrity of Senator Gallagher.