Taoiseach Brian Cowen last night insisted he had secured enough support to win tonight's vote.
A defiant Mr Cowen said he remained confident of the outcome, despite numerous ministers and TDs refusing to come out and publicly support him.
And he signalled that he may yet take a tougher approach with his leadership rival, Micheal Martin, if he wins tonight's crucial vote.
Mr Martin's offer to resign from the Cabinet "comes up for consideration" when the result of the vote by 71 Fianna Fail TDs becomes known, the Taoiseach said.
He said that Mr Martin's weekend offer to resign wasn't necessary "at the time".
"As he (Mr Martin) has said also, of course, is that the resignation offer remains on the table. It's a matter for a Taoiseach, in the aftermath of that decision, to decide what's best.
"I don't want to make or indicate what the outcome is until such a time as we have had the vote," Mr Cowen said yesterday.
Former Defence Minister Willie O'Dea and junior minister Billie Kelleher were among eight TDs who declared they would be voting against the motion of confidence in Mr Cowen.
The Taoiseach said Mr O'Dea had come to a "political assessment", which he respected.
"I've heard from all colleagues. Willie, as he was saying, was giving his own opinion, having been speaking to others," Mr Cowen said.
The Taoiseach insisted the "wider perspective" of the party had led him to believe he could win the motion of confidence.
"I remain confident of the outcome. My decision to have a confidence vote will enable us to put this matter to rest once and for all for the foreseeable future," Mr Cowen said.