President Carolos Papoulias was under pressure on Saturday to orchestrate a way out of Greece's political impasse as fresh elections appeared increasingly likely.
The president must step in after three failed attempts to form a coalition government following inconclusive elections in the debt-strapped country.
The nation is deeply torn over tough austerity measures imposed as conditions for its IMF-EU bailouts, and the crisis has raised the specture of a default and exit from the 17-member eurozone.
"We're a breath away from the drachma and disaster," liberal daily Kathimerini warned on Saturday. "A very large segment of our fellow citizens do not realise it, and this is very dangerous."
Voters last Sunday punished the mainstream parties and left a fractured political landscape amid intense EU pressure over Greek finances.
Socialist Pasok leader Evangelos Venizelos on Friday failed in the latest bid to form a government after the radical leftist Syriza party refused to join a pro-austerity coalition with the socialists and conservatives.
Venizelos was to return his mandate to Papoulias at 1000 GMT.
The head of state is then expected to urge party leaders to form a national unity government, by Monday at the latest.
If the parties cannot agree a compromise by next Thursday, new elections will have to be called.
"The president is now called to attempt to find a solution," said financial daily Naftemboriki. It added that the man who had held together Greece's previous uneasy coalition, former ECB deputy chief Lucas Papademos, had told Papoulias on Friday that he would not remain as caretaker prime minsiter in the event of repeat elections.
The latest twist in the tortuous political drama came as EU paymaster Germany threatened to cut off the country's loan lifeline and hinted that the crisis-ridden eurozone could get along without Greece.
Venizelos was the third party leader who tried and failed to cobble together a government after the inconclusive elections.
"I am going to inform the president of the Republic (Saturday) and I hope that during the meeting with Carolos Papoulias, each party will assume its responsibilities," Venizelos told reporters in Athens.
Venizelos had been hoping to win the support of Syriza, a party deeply opposed to the terms of the 240 billion euro (311 billion dollar) European Union-International Monetary Fund bailout and which surged to second place in Sunday's vote.
Earlier, another possible ally, the small Democratic Left party, said it would not join a government made up of only Pasok and the conservative New Democracy party that did not include Syriza.
Both Syriza and the New Democracy party had failed in their own attempts to assemble a coalition government.
Two new opinion polls have shown that Syriza could even emerge as the victor if new elections are held in June.
Brussels on Friday revised downwards its economic forecasts for the country at the epicentre of the eurozone debt crisis.
The European Commission said the economy is expected to contract by 4.7% this year and see zero growth next year.
Fitch credit rating agency warned that the emergence of a Greek government "unwilling or unable to abide by the terms of the current EU-IMF programme would increase the risk of Greece leaving the eurozone."
"If they are required, the re-run elections will therefore be a critical event for both Greece and for the eurozone," it said in a note.
Greece has already committed to finding in June another 11.5 billion euros in savings over the next two years. It also needs to redeem 436 million euros in maturing debt on May 15.