The citizenship crisis has taken another twist with a Liberal candidate blocked from replacing former minister Fiona Nash by the High Court.
Ms Nash was disqualified by the High Court on October 27 because she held dual citizenship, in breach of section 44 of the constitution.
Hollie Hughes was next candidate down the NSW coalition Senate ticket behind the then-Nationals deputy at the 2016 election and due to take Ms Nash's seat following a court-ordered special count
However, the court on Wednesday ruled she couldn't take up the seat because she was also disqualified.
Ms Hughes was appointed a part-time member of the Administrative Appeals Tribunal on July 1, which the government admitted to the court was an "office of profit under the Crown".
The government argued this should not disqualify her as she did not hold the position between her nomination for election and the declaration of the election result in 2016.
However the court heard the fact she held the AAT position between September 4-5, when the Senate resolved to refer the Nash case to the court, and October 27, should render her ineligible.
AAP understands Ms Hughes was advised by the commonwealth not to take her case to the court but decided to anyway.
It is expected if there is another special count the seat could go to Liberal and key Tony Abbott all, Major General Jim Molan.
Mr Abbott said the court's decision had to be respected even though most people would have considered Ms Hughes eligible.
"If that means Jim Molan gets the guernsey, well, he is a great man and he will do a good job," he told 2GB radio.
Labor senator Penny Wong said it was a "humiliating defeat" for the government.
Geoffrey Kennett SC, who was appointed by the court to take a contrary view to the commonwealth, said there was a "risk to responsible government" in allowing a failed candidate to take up a government position and then resign it to take up a seat in parliament.
He rejected the argument that the "choosing" process ended on election day because there were other methods of "choosing" including Senate casual vacancies and in the case of an automatic win, when only one candidate stood in a seat.
The decision has senior government figures fearing that any former candidates may be barred from taking up taxpayer-funded jobs for six years after a Senate election.
There could also be a cloud over new Greens senator Andrew Bartlett, who replaced Larissa Waters this week after the court found she was ineligible due to her dual citizenship.
Solicitor-General Stephen Donaghue told the court the position of Senator Bartlett - who formerly held a university job - had not been tested and there was nothing preventing the Senate from referring him to the court to test his eligibility.
Senator Bartlett says he has "strong advice" a university position is not an office of profit under the Crown and doesn't disqualify a candidate.