Reinvigorated by its win in the Bennelong by-election, the Turnbull Government has refreshed its threat to refer Labor and crossbench MPs to the High Court over their citizenship.
John Alexander's win in the crucial vote has given the Coalition back its 76-vote majority in the Lower House, and the numbers to act unilaterally in forcing more High Court challenges.
The Federal Government argues that Queensland Labor MP Susan Lamb, WA's Josh Wilson and Tasmanian Justine Keay, along with Nick Xenophon Team MP Rebekha Sharkie from South Australia should throw themselves at the mercy of the highest legal authority in the land.
All were still British citizens at the time nominations closed before last year's federal election.
"As the Government has always stated, our first preference is for Bill Shorten to do the right thing and refer his own members of Parliament to the High Court," Leader of the House Christopher Pyne told the ABC.
"In the absence of that, we will refer any MP with a serious case to answer."
Labor maintains there are Coalition members who have failed to adequately prove they were not dual citizens.
Among them are Sydney-based MP Jason Falinski and Victorian member Julia Banks.
Labor has already referred citizenship questions about Lower House MP David Feeney and ACT senator Katy Gallagher.
The Opposition unsuccessfully tried to refer another eight MPs to the High Court, including Labor and Coalition members, in the last sitting week of Parliament.
However, the Government used its numbers to block the vote.
The four members targeted by the Coalition all say they took "all reasonable steps" to renounce their British citizenship ahead of the last election.
Despite attempts to resolve the citizenship fiasco by the end of the parliamentary year, the stand-off between the major parties continues to inflame tensions.
