SYDNEY (Reuters) - Australia's parliament speaker said on Sunday he was temporarily stepping down over a sexual harassment lawsuit which threatens to further weaken Prime Minister Julia Gillard's hold on power.
Gillard's Labor government has suffered poor poll figures in recent months which give a big lead to the conservative opposition under Tony Abbott.
Speaker Peter Slipper issued a statement "emphatically" denying all allegations against him by a male former staff member, who says the speaker sexually harassed him.
But Slipper said he could not continue in his role pending investigation of the allegations in a suit filed in Australia's Federal Court in Sydney on Friday.
"The allegations include both a claim of criminal behavior and a claim under civil law," Slipper said in the statement issued after he returned from a trip to the United States.
"As such I believe it is appropriate for me to stand aside as speaker while this criminal allegation is resolved."
Slipper, 62, indicated he would retain his seat in parliament.
Former staffer James Hunter Ashby, 33, also alleges misuse of taxpayer-funded taxi dockets by Slipper in the lawsuit.
The government holds an effective one-vote majority in the 150-member House of Representatives, parliament's lower chamber, thanks to votes from independents.
Deputy Speaker Anna Burke is to act as speaker for the interim. Opposition leaders have called on Slipper to resign from his seat, a move that would force a critical by-election.
Slipper's departure could potentially throw the slender majority into doubt as Gillard would have to find another member of parliament to replace him.
Gillard's position was bolstered when Slipper last year became speaker after defecting from the opposition in a move backed by the prime minister. The speaker's position is ceremonial, but his casting vote can be significant in the event of a tie, where the speaker traditionally votes with the government.
Analysts said the row, however embarrassing, would not bring down Gillard's government just yet as independents backing her were unlikely to withdraw support and force a new election in which they could lose their seats.
"It is the latest in a litany of disasters that they have to deal with," said Nick Economou of Melbourne's Monash University. "Mr Abbott will have a massive, massive majority. The government and its hangers-on won't want this to end prematurely."