ATHENS, Greece – Another attempt to assemble a new coalition government in Greece collapsed Thursday, adding to concerns that the country won’t be able to continue with European Union-mandated austerity measures and instead will be forced into default and even expulsion from the euro currency zone.

Alexis Tsipras, the firebrand politician whose Radical Left coalition finished second in Sunday’s polls, gave up his attempt to form a leftist government opposed to the terms of an international Greek bailout. That followed the decision Monday by the first-place finisher, Antonis Samaras of the right-of-center New Democracy, to abandon his attempt to form a pro-bailout coalition.

That leaves Evangelos Venizelos of the Socialist PASOK, who took a severe beating and finished third in the polls. But he has indicated that he has little hope of forming a stable government that would impose additional taxes and spending cuts as promised to the EU.

The only chance of avoiding another round of elections would be if centrist parties agree to a narrowly based government of national salvation. After an initial meeting with Venizelos, Kuvelis Fotis, leader of the splinter Democratic Left party, publicly indicated support for that option.

Leftists are almost certain to oppose it, however, and will probably take to the streets in protest.

New elections could be announced as soon as Sunday.

Tsipras, whose party almost quadrupled its support in the May 6 poll, rattled European leaders and scared off the two Greek centrist parties by calling for abandonment of the tough EU austerity program as well as for nationalizing the country’s banks.