Federal Labor is refusing to release documents showing their members and senators meet the citizenship requirements outlined in the constitution.

As the citizenship crisis sweeps through Canberra, there is growing pressure on the Opposition to prove members who were born overseas or who have family links to other countries are not dual citizens.

The Federal Government has raised questions over the citizenship status of a number of Labor MPs, including Susan Lamb, Justine Keay, Maria Vamvakinou and Tony Zappia.

But despite repeated requests from the ABC, the party has refused to release any of the documentation those members are relying on to remain in Parliament.

The constitution prevents anyone with dual citizenship from holding office, and there are now seven politicians, including the Deputy Prime Minister and Nationals leader Barnaby Joyce, who will ask the High Court to decide whether they can remain in Parliament.

The Labor Party argued its vetting procedures were more strict than their political rivals, and all its members were in the clear.

It said that when a prospective member of parliament nominates for election, candidates are asked where their parents and grandparents were born and show relevant documentation.

Last week, Susan Lamb released a statement saying she had begun the steps to renounce her British citizenship in May 2016, ahead of the July election.

Justine Keay also issued a statement arguing she had taken all relevant steps to renounce her British citizenship ahead of the poll.

Tony Zappia and Maria Vamvakinou claimed they had received letters from the Italian and Greek Consulates confirming they had renounced their foreign citizenship ahead of entering Parliament.

Questions over citizenship a distraction: Shorten

Earlier, Opposition Leader Bill Shorten labelled reports he too may be a dual citizen as an attempt by the Coalition to distract from the farcical state of Federal Parliament.

"I'm fully aware that the Government is desperately trying to peddle its newest conspiracy that I'm a secret English agent," Mr Shorten said.

"I renounced my citizenship in 2006, and there's no whiff of evidence of anything to the contrary."

On the ABC's Q&A program on Monday night, he resisted calls to produce evidence he was not a dual citizen.

Sorry, this video has expired Bill Shorten says he won't hand over papers proving he's not a British citizen

Australian Conservatives senator Cory Bernardi suggested the current session of Parliament should be ended, or prorogued, because of the growing number of members and senators facing questions over their allegiance.

Mr Shorten said the Government should postpone debate on contentious legislation until the High Court cleared up the crisis.

"I don't know if we need to go to proroguing, that seems a pretty drastic step," Mr Shorten said.

"But it does seem to me that if we're not going to have gridlock in the Parliament through self-inflicted parliamentary farce by the Government, let's just work together."