Irish Prime Minister Brian Cowen is preparing for a vote on his leadership with a key minister publicly questioning his judgment.Mr Cowen said he was confident of winning the secret ballot among Fianna Fail MPs, months after Ireland accepted an 85bn-euro ($113bn) bail-out.
But despite voicing support for his leader, Finance Minister Brian Lenihan accused him of "lapses of judgment". An election could be called if Mr Cowen loses his party's support.
After spending the past year trying to save Ireland's economy, he is now fighting for his own survival, the BBC Ireland correspondent, Mark Simpson, reports.
On Sunday, Foreign Minister Micheal Martin, previously loyal to Mr Cowen, suddenly turned against him, our correspondent says. Mr Martin said he believed Fianna Fail now needed a new leader.
While Mr Cowen believes he has enough backing to stay in the job, his problem is that Tuesday evening's vote is private - it is not just a show of hands.
And his opponents say that the secret ballot could be their secret weapon, our correspondent notes.
The winner needs to take at least 36 of the 71 votes.
Cowen confident Mr Cowen said Fianna Fail was in a fight for public support and that he was the fighter it needed.
"I remain confident obviously of the outcome," he said.
"I think my decision to have a confidence vote will enable us to put this matter to rest once and for all for the foreseeable future.
"From my point of view, it is clearly the case that the settled view of the party is that I should lead Fianna Fail."
He won the endorsement of Transport Minister Noel Dempsey, who is standing down at the election.
But Mr Martin, Mr Cowen's main challenger, argued that a change in leader would put fire in the belly of party workers and supporters.
'I was not happy' The finance minister, who is also seen as a contender for the party leadership, went on the attack, despite pledging his support for Mr Cowen.
He hit out at recently revealed contacts between the Taoiseach (Mr Cowen's Irish title) and Anglo-Irish Bank (AIB) bosses as the bank neared collapse.
These involved a golf game and dinner at the Druid's Glen resort in Wicklow and a direct phone call with bankrupt ex-AIB chairman Sean FitzPatrick from Malaysia in 2008.
But Mr Lenihan also revived six-month-old allegations that Mr Cowen had sounded hungover in a live broadcast from Galway. "The Taoiseach has had his difficulties," Mr Lenihan said.
"I'll make no secret of the fact that I was not happy with what happened in Galway in connection with the interview and the recent developments in relation to a certain golf game he had.
"I think they showed lapses of judgment."
Mr Cowen has denied his contacts with AIB influenced in any way the introduction of a state-backed bank guarantee scheme. He has also denied he was drunk or hungover during the Galway interview, dismissing the allegations as a pathetic stunt and a new low for politics. On his own political future, Mr Lenihan said he had been "very flattered" at suggestions he should lead Fianna Fail but Mr Cowen was the best person to "lead us into this election". Do you think Irish Prime Minister Brian Cowen can win the confidence vote? Does Fianna Fail need a new leader? Is a secret ballot the answer?