Australians in half a dozen federal seats could be forced back to the polls, as Malcolm Turnbull received Greens support to refer all MPs with "legitimate question marks" over their citizenship to the High Court.

But the Greens will still push ahead with a motion in the Senate on Monday to set up an independent audit of all 226 MPs to end the citizenship crisis and restore stability.

The prime minister has proposed that all MPs lodge details, on a public register, of their family history and renunciation of foreign citizenship by December 7.

He is awaiting agreement from Opposition Leader Bill Shorten, who wants a December 1 deadline and the release of a "High Court standard" level of detail from MPs.

However, Labor is concerned the government will use its one-seat majority in the lower house to target potentially in-doubt opposition MPs.

Mr Turnbull said he would present his resolution to the Senate and lower house whether or not Labor supported it, and consider referring Labor MPs to the court.

"We referred our own people to the High Court when we had advice that they weren't in breach," he told reporters on the sidelines of the APEC summit in Vietnam.

"When you've got (Labor) people that were on their own admission UK citizens at the time they nominated... it really is a bit rich of Mr Shorten to say to me that the government shouldn't vote to refer them."

The stand-off continued as the High Court put a hold on the confirmation of Liberal candidate Hollie Hughes to replace disqualified Nationals deputy leader Fiona Nash.

The court will consider next Wednesday whether Ms Hughes' job with the Administrative Appeals Tribunal, which she later quit, disqualifies her.

The court cleared the way for three new senators to replace Malcolm Roberts, Larissa Waters and Scott Ludlam.

One MP who may not wait for the disclosure process is Liberal John Alexander, who is weighing up whether to quit over his dual citizenship and trigger a by-election in the Sydney seat of Bennelong as early as December 16.

That would put pressure on Labor to deal with doubts over as many as four MPs - Justine Keay, Madeleine King, Susan Lamb and Josh Wilson - and for crossbencher Rebekha Starkie to consider her position.

Ms Keay waited three months before following the advice of Labor officials and renounced her British citizenship after the 2016 election was called, and believes the court may be the best place to clarify her eligibility.

Mr Shorten told reporters in Perth he was "confident" all Labor members had no legal problems because of the party's candidate vetting process.

He rejected the December 7 deadline saying it would cost almost $1 million to bring parliament back the following week to deal with any court referrals.

Greens leader Richard Di Natale said uncertainty over renunciation dates was enough to warrant a court referral, as was having an overseas-born parent.

Senator Di Natale is seeking advice on whether Governor-General Sir Peter Cosgrove could be petitioned to dissolve the parliament.

Mr Turnbull refused to say whether he had discussed the government's stability with Sir Peter.

"I never comment on discussions with the governor-general," he said.

Nor would he speculate on what number of by-elections would be too many.