Alexis Tsipras of Greece’s Syriza party squared off with political leaders before talks on forming a coalition, handing them an ultimatum to renounce support for the European Union-led rescue if they want to enter government.

Tsipras said he expected Antonis Samaras of New Democracy and Evangelos Venizelos, the former finance minister who leads the Pasok party, to send a letter to the EU revoking their written pledges to implement austerity measures by the time he meets them today to discuss a government alliance. Samaras and Venizelos rejected the request. Samaras said he was being asked “to put my signature to the destruction of Greece.”

“He interprets, with unbelievable arrogance, the election result as a mandate to drag the country into chaos,” Samaras said late yesterday in televised remarks. “I hope Mr Tsipras will have come to his senses by the time we meet.” Tsipras is due to meet with political leaders from about 5 p.m. in Athens.

The stand-off since the inconclusive May 6 election has reignited European concerns over Greece’s ability to hold to the terms of its two bailouts negotiated since May 2010. With Parliament split and policy makers in Berlin and Brussels urging Greece to stay the course, the country at the epicenter of the debt crisis is again facing the risk of an exit from the euro.