Green Party leader John Gormley has called for a General Election to be held in Ireland in the second half of January 2011, RTE reports
At a specially convened news conference this morning, Gormley said the election must take place in the second half of January.
The leader of the Government's junior coalition partner said that three things needed to be done: produce a credible four-year plan, deliver a Budget for 2011, and secure funding support from the European Union and International Monetary Fund.
Gormley said the party had always said it would only continue in Government as long as it would benefit the people, but leaving the country without a Government would be damaging and breach duty of care.
The Green Party leader said that people felt misled and betrayed.
The party had now reached a point where the Irish people need political certainty to take them beyond the coming two months, he said.
The decision was made last Saturday after a long series of meetings, he said.
The last three weeks had been traumatic for Irish people, he added.
"Since entering Government in June 2007, we in the Green Party have worked to fix and reform the economy. It has been difficult. We have taken tough decisions and put the national interest first," he said.
Gormley said in recent days there was a real problem in terms of communications and the answers the Greens got were not clear enough.
He said the party felt they needed clarity around the issues.
Green Party Chairman Dan Boyle has said the party made its decision because of the need for economic and political certainty.
He said they had decided not to pull out of Government now because it could compromise key elements of the negotiations between the Government and the EU and IMF.
Green Party Education Spokesman Paul Gogarty said the Government has become untenable and people want an election.
Gogarty said he did not think Fianna Fáil liked the party's decision but he said the writing was on the wall.
Fianna Fáil leadership
A spokesman for the Taoiseach said the Government's focus remains firmly on the Budget and the four-year plan.
Gormley only made the Taoiseach aware of his party's decision minutes before his announcement, it has emerged.
The development appears to have taken Brian Cowen by surprise, who was giving an interview on local radio while Mr Gormley was trying to contact him.
The Taoiseach received the news at 11.30am, just minutes before the Green Party press conference.
Effectively it means the election campaign has begun, putting the Government in an extremely difficult position.
In equally sharp focus for Fianna Fáil now is Mr Cowen's leadership.
Earlier, Mary O'Rourke TD said that the Fianna Fáil parliamentary party should meet early in the New Year to discuss its leadership and future direction.
Speaking in Athlone, O'Rourke said that while she believed the Taoiseach had credibility after receiving the support of his colleagues at European level, the appropriate time to discuss his leadership would not be until the Budget had been passed.
Her comments follow renewed calls by backbenchers Noel O'Flynn and Mattie McGrath for Brian Cowen to resign after the Budget.
Fianna Fáil Junior Minister Sean Connick has said the issue of leadership will have to come up when an election is called.
He added that he would not be in support of removing the Taoiseach at this point in time.
Meanwhile, the Labour Party has said the Green Party is jumping from a sinking ship.
Pat Rabbitte said that the party has been a "pathetic and weak influence in Government" and has no future politically.
The Labour TD said nothing from Government can be believed and what really inspired this decision announced today may never be known.
He said the party will now claim it was them who brought on the election and he said the move was ' one-upmanship' of the highest order.
Independent TD Jackie Healy-Rea has called for a General Election.
In a statement, he said it was time for an election to stop 'this charade of spin and lies'.
Healy-Rae said: "The time has come when I no longer can honor my word to this Fianna Fáil-led Government, the time has come to say stop, the time has come for the truth to be told to the Irish people; the time has come for integrity and honesty in political leadership."