Ireland's deeply unpopular prime minister suffered another blow Sunday as the small but pivotal Green Party withdrew from his coalition government, forcing a national election to be held next month rather than March and raising pressure on the premier to quit.

Brian Cowen is widely blamed for Ireland's stunning slide to the brink of bankruptcy. His Fianna Fail party, which has won the most seats in parliament in every election since 1932, is expected this time to suffer a crushing defeat.

The Greens hold just six seats, but losing them cost the ruling coalition its parliamentary majority. Their withdrawal means Cowen will be forced to dissolve parliament and call an election within days, nullifying the March 11 election date Cowen had announced last week. Analysts said a new election date, most likely in the second half of February, would be pinpointed this week.

Cowen ruled out resigning as prime minister before the passage of the 2011 Finance Bill, a deficit-fighting measure that will broadly raise income taxes as part of Ireland's international bailout.

"It's important that we get the Finance Bill through, and we need a government to do that," said Cowen, who did resign Saturday as leader of Fianna Fail.

Ireland's government has been heading for collapse since November, when Cowen was forced to negotiate a euro67.5 billion ($91 billion) loan agreement with the European Union and International Monetary Fund to prevent national bankruptcy.

The collapse reflects a wider debt crisis in Europe: Greece required a bailout before Ireland did, many analysts predict Portugal will be next, and nations across the continent are imposing painful cuts to claw back deficits.

The Greens announced in November they would leave the government, sinking it, as soon as all legislation linked to the bailout was passed. They and opposition parties have grown frustrated at Cowen's slow rollout of the Finance Bill, which will aggressively raise income taxes to combat Ireland's Europe-leading deficit. It was published Friday afternoon, whereas other bailout-linked bills were passed rapidly more than a month ago.

"Our patience has reached an end," said Green leader John Gormley, who called on Fianna Fail to agree to accelerate passage of the Finance Bill as the government's dying act. Gormley said his six lawmakers would vote for the bill.

"The Irish people want to see political certainty, economic certainty, and they do want an election," said Gormley, whose environmentalist party joined the Irish government in 2007.

Cowen said his shrinking government intended to negotiate a timetable Monday with opposition lawmakers. But he said it would be impossible to meet opposition demands for the entire bill to be debated, amended and passed into law by Friday.

The two major opposition parties, Fine Gael and Labour, are threatening to force a no-confidence vote in parliament this week against Cowen. Labour said it had no intention of backing down unless Cowen commits to dissolving the parliament for an election by Friday.

"Fianna Fail will have to stop procrastinating and say: It's over. We don't want another weekend of this uncertainty," Labour lawmaker Pat Rabbitte said. "We need to let battle be joined, let the people decide, and let a government that has the prospect of four or five years in office be elected."

Gormley appealed to Fine Gael and Labour to hold fire until the Finance Bill is passed by the fastest responsible means.

"It does need to pass. It's genuinely in the national interest that that happens," Gormley said.

Sunday's Green withdrawal means Cowen has already lost two more Cabinet ministers: Environment Minister Gormley and Communications Minister Eamon Ryan. Cowen has only seven of 15 Cabinet ministers remaining — the bare minimum permitted by Ireland's constitution — following his disastrous management of an attempted Cabinet reshuffle last week.

Fianna Fail has won the last six elections dating to 1987, but its age of dominance is facing an inglorious end. A Sunday newspaper poll put Fianna Fail's nationwide support at just 8 percent.

(This version corrects spelling of Cowan in long headline and corrects that Fianna Fail won last six election but did not form last six governments.)