Prime Minister Julia Gillard Monday defended her appointment of Peter Slipper as Australia's speaker as court documents alleged he used his position to pursue sexual relations with male employees.
The married Slipper, 62, stood aside from his role on Sunday after claims he harassed former aide James Ashby, 33, with explicit text messages, unwanted advances and inappropriate comments between January and March this year.
He is also accused of fraudulently misusing taxpayer-funded taxi services.
In Federal Court documents published Monday, Ashby accused Slipper, an ordained Anglican priest, of "using his position to pursue relationships of a sexual nature with young male employees".
Ashby, who is openly gay, claimed the Commonwealth knew that in 2003 Slipper, who was then a Liberal MP, had a sexual relationship with another younger male member of his staff.
He alleges the Commonwealth "failed to take reasonable and effective steps to prevent (Mr Slipper) from utilising his office to foster sexual relationships with young male staff members".
Ashby is seeking compensation and orders for his former employer to undergo counselling and anti-discrimination training.
Slipper has denied all the allegations. Besides the civil proceedings over the harassment claim, he is also facing an investigation into the possible criminal misuse of taxi vouchers.
News Limited Monday published more allegations, claiming he also breached rules relating to MPs travel entitlements. Slipper has yet to respond to these but tweeted his thanks to those "who have offered strong support".
Slipper defected from Tony Abbott's Liberal Party last year so he could be appointed speaker. It stripped one vote from the opposition and shored up Julia Gillard's ruling Labor Party's wafer-thin hold on power.
Gillard said she had not spoken to him in recent days but defended her judgement in engineering his promotion to the role last year, saying she appointed him on merit.
"I don't claim to know Mr Slipper personally or well but I formed a professional judgment about his ability to do the job," she told reporters in Singapore.
"And Mr Slipper, as he has done his work as speaker, has kept firm control of the parliament particularly during what can be quite a raucous period -- question time."
But she said it was appropriate that he stood aside.
"Australians rightly expect parliamentarians to play by the rules and to uphold the respect and integrity of the Australian parliament," she said.
His decision to step aside leaves Gillard's minority Labor government on a parliamentary knife-edge, reducing their numbers in the lower house to 74 with Slipper unable to vote while stood down. The opposition has 73 votes.
Opposition leader Tony Abbott launched a scathing attack on Gillard's integrity for picking Slipper, despite his own party having pre-selected him nine times in the past before he defected.
"This was a squalid and tawdry deal entirely masterminded by the prime minister to protect her own political position," he said.
"He only assumed the chair because she engineered it. This government should have long ago died of shame."