Bill Shorten says he is not a "secret English agent" adding that he renounced his British ties in 2006.
The opposition leader, whose father was born in England, has been accused by the government of not being forthright in relation to the citizenship issue that has engulfed seven MPs.
"I am fully aware that the government is desperately trying to peddle its newest conspiracy, that I am a secret English agent," Mr Shorten told reporters in Sydney on Monday.
"The reality is that no, I am not. I renounced my citizenship in 2006 - there is no whiff of evidence of anything to the contrary."
Attorney-General George Brandis said on Sunday, the coalition, the Greens and One Nation had been "up-front" about citizenship issues and the only party playing games about it was Labor.
He accused Mr Shorten of a "don't ask, don't tell" policy.
Mr Shorten said there was no cloud over any Labor MP.
He said the prime minister needed to explain why he let one minister, Matt Canavan, stand down over his constitutional eligibility while two others, Barnaby Joyce and Fiona Nash, remained in cabinet.
The ministers should be put on the interchange bench and debates on controversial legislation in parliament set aside until the High Court adjudicated on the citizenship cases, he said.
"We can't have the government frozen like a wallaby in the headlights - we have to park the eligibility conversation," Mr Shorten said.
The High Court will hold a directions hearing on Thursday in the cases of Senator Canavan, Mr Joyce, One Nation senator Malcolm Roberts and Greens senators Scott Ludlam and Larissa Waters.
The government believes the court may not hand down any decisions until October.