The Minister for Trade and Commerce, Billy Kelleher, today joined rebel ranks trying to oust Taoiseach Brian Cowen as leader of Fianna Fail party.
As Foreign Affairs Minister Micheal Martin claimed other Cabinet members also wanted change, Billy Kelleher said he would vote to end Mr Cowen's rule.
Mr Kelleher warned he also believed the majority of Government ministers and backbenchers wanted change.
The junior minister claimed Fianna Fail had failed to communicate properly with the public.
"The reality is that Fianna Fail must recognise the current climate of public opinion, and I believe the time has come for a change of leader who will put forward a positive agenda and engage with the public," the junior minister said.
Mr Martin has led the charge against the Taoiseach, claiming that the survival of the party is at stake at the next election, due in March.
He claimed there was back-biting and whispers in the party throughout last year over Mr Cowen's leadership.
The Taoiseach broke with protocol last night to announce he would put forward a motion of confidence in himself in a secret ballot at Tuesday's meeting of the parliamentary party. He needs 36 votes to survive.
Two other senior Cabinet members, Finance Minister Brian Lenihan and Tourism Minister Mary Hanafin - both put up as potential leadership candidates - have yet to declare their hand.
Mr Martin has tendered his resignation amid the crisis. The Taoiseach refused to accept it but the offer will stay on the table until the issue is resolved at tomorrow's secret vote.
The Foreign Affairs Minister said party members around the country have warned him that they do not want Mr Cowen as leader in the election campaign.
Mr Martin said he believed TDs had told the Taoiseach to put the leadership issue to bed one way or another and that a vote should have been held earlier.
"I have made my decision and I haven't sought support from others," the minister said.
"I would be aware of Cabinet ministers who would have similar views but it's for them to make their views known."
Government Chief Whip John Curran said he had not heard of any other minister backing Mr Martin.
"Brian Cowen, staying on not just as Taoiseach but as leader of Fianna Fail, is prepared for the battle," Mr Curran said.
Mr Martin insisted he did not feel isolated.
The numbers voting for or against the Taoiseach in the secret ballot will not be made known.
Noel O'Flynn, a backbencher who has declared in favour of Mr Martin, said he wanted change after watching the party's slump in opinion polls as well as the popularity of the Taoiseach.
"We're looking at the possible wipeout of the party," Mr O'Flynn said.
Mr Cowen said he was confident he would survive the motion.
"I'm confident of the outcome," the Taoiseach told Clare FM.
"I had a very detailed consultation with all TDs in the party. I'm very heartened by that process."
He signalled the issue of Mr Martin's resignation may arise after the parliamentary party meeting.
"Micheal has made the offer of resignation and I told him that it is not something I would accept at the present time while this debate is going on and we'll see in the aftermath of the parliamentary party meeting what the right and proper course of action to take is," he said.
IT was Enda Kenny who spotted the internal tension at play within Fianna Fail. Last Wednesday in the Dail, as Brian Cowen explained his golf outing with Sean FitzPatrick, Micheal Martin sat further away from the Taoiseach than usual, studiously examining his performance.