Prime Minister Malcolm Turnbull is trying to end the uncertainty over the citizenship of politicians.

Key points: MPs and senators would be asked to lodge a declaration including details about any country other than Australia where they may be a citizen

MPs and senators would be asked to lodge a declaration including details about any country other than Australia where they may be a citizen Penalty for providing a false declaration unclear, PM says it would be up to the Parliament to decide

Penalty for providing a false declaration unclear, PM says it would be up to the Parliament to decide Once both houses agree, politicians will have 21 days to lodge

He has announced a plan to force MPs and senators to lodge a declaration when they are elected that they are not a citizen of any country other than Australia.

Mr Turnbull said his plan would mean if politicians had ever been citizens of another country, they would have to say where and when they renounced it.

The new system would be overseen by the parliamentary office that keeps track of politicians financial interests.

The announcement comes days after Liberal senator Stephen Parry joined the growing ranks of federal politicians whose dual citizenship has rendered them ineligible to serve the parliament, according to section 44 of the constitution.

The High Court found former deputy prime minister Barnaby Joyce and senators Fiona Nash, Scott Ludlam, Larissa Waters and Malcolm Roberts had all breached that section of the constitution.

The AEC is recounting the Senate tickets for the ousted senators while Mr Joyce is facing a by-election in his seat of New England.

The High Court ruling had prompted calls from the Greens for a cross-party audit, but both major parties had resisted that idea.

"This is not an audit. The obligation is on each member and each senator to make a full disclosure as I have repeatedly said in recent times," Mr Turnbull said.

PM concedes some MPs may still fall foul of section 44

Mr Turnbull said the new requirements might lead to some people resigning from Parliament if they found that their documentation did not back their eligibility.

He also foreshadowed that some MPs would challenge others on the basis of the paperwork provided.

But the PM said the Liberal Party's federal director had told him that all Liberals believed they were in compliance with the constitution.

Last week Mr Turnbull strongly resisted taking any action on the citizenship issue, saying it would be a witch hunt.

But today he called it transparency and argued that his plan still put the onus on each politician to prove their own eligibility.

Once both houses agree to the new measure, all MPs and senators will have 21 days to make declarations.

The requirements will also apply to new members sworn in.

This is the full statement of the proposed requirements:

The House resolves that one, not later than 21 days from the date of the resolution and in subsequent parliaments being sworn in as a member, each member shall provide to the registrar of members interests a statement containing the following columns: a) declaration by the member that at that time the member nominated for election to the House of Representatives he or she was not, to the best of his or her knowledge and belief, a citizen of any country other than Australia; b) the declaration that the member, to the best of his or her knowledge and belief, is not a citizen of any other country apart from Australia; c) so far as the member is aware, the place and date of the member's birth and citizenship which the member held at the time of birth; d) so far as the member is aware, the place and date of the birth of the member's parents; e) whether, to the best of the member's knowledgeable, the member has ever been a citizen of another country, and if so, which country or countries; and f) if the member has entered the previous questions in the affirmative, then provide details and evidence of the time and manner in which the member's citizenship of the other country was renounced or otherwise came to an end that.

PM wants to talk with Shorten about plan today

Mr Turnbull said he wanted to speak to Labor leader Bill Shorten about the plan today.

He said he wanted it introduced quickly, saying the Senate could vote for it next week and the House of Representatives could implement it when it meets at the end of this month.

Mr Turnbull said he was optimistic that his idea would be agreed to.

Last Friday, Mr Shorten announced his own plan for sorting out the citizenship debacle that has been paralysing the Government.

The system Mr Turnbull has just announced appears similar to the scheme Mr Shorten unveiled.

Mr Shorten said he would talk to Mr Turnbull about the plan, but said it was a big turnaround from last week when the PM was "arrogant and sneering" about the Labor idea.

He said he would press Mr Turnbull for details and would not agree to anything that would be a "whitewash".

Greens leader Richard di Natale said Mr Turnbull's plan was no solution to the crisis before us.

Senator di Natale argued for an independent review of politicians' citizenship by legal experts.

What would the penalty be for false declarations?

Mr Turnbull said any MP found to have made a false declaration would be found in contempt of the parliament.

He said it would be up to the parliament to decide what the penalty for that should be.

According to Senate procedural documents, the maximum penalty for contempt of parliament is "imprisonment or the imposition of a fine", but the Senate has never imposed such a penalty.

The House of Representatives' procedure lists similar penalties, however, it states there has been considerable uncertainty as to whether it has the power to impose fines.

It has only imposed a penalty of imprisonment for contempt once, in 1955.

"Mr R E Fitzpatrick and Mr F C Browne were found guilty of a serious breach of privilege by publishing articles intended to influence and intimidate a member in his conduct in the House. They were each imprisoned for three months."