The citizenship spotlight has fallen on firebrand independent Jacqui Lambie as Malcolm Turnbull and Bill Shorten quibble over the details of a plan to end the crisis once and for all.

Senator Lambie revealed in a statement on Wednesday her father was born in Scotland but said she had “no concerns” she was a dual citizen.

The Tasmanian politician claimed she had learned more about her father’s background “in recent weeks” while writing her autobiography.

“I’m happy to put on record that I’m satisfied that my parents are both Australian citizens and I have no concerns about me being a dual citizen because of where they were born or came from,” she said.

“As far as I’m concerned all their affairs are in order as are mine.

“A citizenship audit of all Parliamentarians will clear the air once and for all which is why I’m supporting such a move 100 per cent.”

A spokeswoman for Senator Lambie declined to answer further questions, such as whether her father had ever held UK citizenship, saying additional details would be revealed through the disclosure process announced by the Prime Minister.

Senator Lambie’s admisssion on Wednesday came after Mr Turnbull and Mr Shorten failed to agree on a process to end the crisis and as the citizenship spotlight turned to two Labor MPs.

No deal for Turnbull, Shorten

The two leaders came together on Wednesday to nut out the details of a citizenship disclosure process announced by Mr Turnbull on Monday, but left without a deal.

The main sticking point, according to Mr Shorten, is Labor’s belief that politicians should be given only five days to produce documentation to back up their eligibility, rather than 21 days as proposed by the government.

Under the Labor proposal, MPs would be asked to make their disclosures on December 1 after Parliament reconvenes for two weeks on November 27.

“We want to sharpen up the Prime Minister’s resolution and make sure it is foolproof,” Mr Shorten said. 

At a separate press conference minutes earlier, Mr Turnbull signalled he would be willing to negotiate over the time period afforded to MPs.

“The timing is absolutely something we are talking about in a constructive way,” he said.

“I am very committed – and always have been – to the disclosures being presented to the Parliament before the end of the year and the House and the Senate being able to consider them,” he added.

The opposition also wanted foreign-born politicians or those with foreign-born parents or grandparents to show how they had investigated and confirmed they did not hold dual citizenship.

Labor MPs in the spotlight

The meeting came a day after Labor accused the government of trying to “skate through” until Christmas and running a “protection racket” to protect Liberal MP John Alexander over his possible dual citizenship.

But with the former tennis star still waiting for confirmation of his status from UK authorities, attention on Wednesday turned to two Labor MPs, Justine Keay and Susan Lamb.

Ms Keay attempted to renounce her UK citizenship before her nomination date, but the British Home Office had only confirmed her application after the election.

Ms Lamb has not revealed documents to show when her renunciation application was accepted by UK authorities.

Labor is confident both MPs took “all reasonable steps” to renounce any possible foreign nationality, citing the High Court’s ruling in the Sykes v Cleary case.

But the government and some experts have argued last month’s unanimous High Court ruling applied a stricter reading of the Section 44(i) of the constitution.

Mr Turnbull said Ms Keay was facing a “real issue”, adding that if “she wishes to maintain her position in the Parliament and not resign, that’s going to involve some considerable legal debate”.

Mr Shorten hit back, accusing Mr Turnbull and his colleagues of “trying to cast aspersions about the legitimacy of Labor MPs”.

“I’m not about to take legal advice from Mr Turnbull, am I?”