Last-ditch efforts by President Karolos Papoulias to broker a deal between wrangling party leaders ended with no deal in sight late Sunday, a week after national elections produced a deadlock, with no party winning enough seats to form a government.
State television said talks would continue Monday evening between the heads of the parties that came in the top three spots in the elections, the conservative New Democracy, radical left-wing Syriza and socialist PASOK, plus the head of the small Democratic Left party, which is in a king-maker position.
But Syriza said it would not attend the talks, state television said, throwing the entire meeting into question.
Syriza head Alexis Tsipras campaigned on a platform for Greece to pull out of its commitments in the international bailout agreement, which has given the country billions in rescue loans. He has insisted he can't back a government that won't overturn the harsh austerity measures taken in return for the bailout.
"Syriza refuses to be a left-wing alibi for a government that will continue the policies the people rejected on May 6," NET state television quoted Tsipras as saying.
Spokesmen for the three other parties said they would attend Monday's meeting.
Voters furious at the handling of Greece's financial crisis and two years of harsh austerity measures taken in return for the bailout loans punished the formerly dominant PASOK and New Democracy, which saw their support crumble to historic lows. Syriza made big gains, more than tripling its popularity to come in second place after campaigning on an anti-bailout platform.
New Democracy head Antonis Samaras, PASOK leader Evangelos Venizelos and Democratic Left head Fotis Kouvelis, agree a coalition must be formed that will work to guarantee Greece's continued presence in the euro, but have insisted it must have the participation or at least the support of Syriza.
In return for €240 billion ($310 billion) in rescue loans from the European Union and International Monetary Fund, Greece has imposed severe spending cuts, including slashing pensions and salaries in the public sector, and repeated rounds of tax hikes. The austerity has left Greece mired in a fifth year of deep recession, with unemployment spiraling above 21 per cent.
"After today's meeting it is obvious they are demanding that Syriza become an accessory to a crime," Tsipras said earlier, after the discussions with the president. "In the name of democracy, of our patriotic duty, we cannot accept this shared guilt. We call on all Greeks to condemn once and for all the forces of the past and to realize that only one hope remains: unity against blackmail in order to prevent the continuing barbarity.
"Fellow Greeks, we can assure you of one thing: we will not betray you."
If no solution can be found, Greece will have to hold new elections next month, prolonging the political uncertainty and bringing the country's continued membership in the euro into doubt.