The leader of a Greek leftist bloc opposed to the country’s austerity measures is set to meet leaders of the debt-stricken country’s main parties in the latest attempt to form a coalition government.Alexis Tsipras, whose Syriza bloc holds 52 seats in the Greek parliament, is demanding that any agreement to form a government would need all parties to agree to reject the country’s EU/IMF bailout deal.He said Greek voters had "clearly nullified the loan agreement” in Sunday’s elections in which support collapsed for the country’s two main parties, which had both backed austerity measures.Syriza came second on Sunday, while the centre-right New Democracy and centre-left PASOK, which between them had 77 per cent of the vote just three years ago, saw their combined share fall to just 32 per cent and PASOK reduced to third place.Both PASOK and New Democracy had backed the terms of a second EU/IMF deal agreed by Lucas Papademos, who was appointed last year to lead a coalition government tasked with rescuing the country from its debt crisis.