Greek voters dealt a blow to eurozone hopes that Athens will stick to its austerity commitments as parties opposing more cuts, including neo-Nazis, won almost 60-percent support in an election Sunday.
According to updated exit polls, the two main parties suffered heavy losses, with the conservative New Democracy and the left-wing Pasok getting just 32.0 to 34.5 percent between them, down from 77.4 percent at the last polls in 2009.
New Democracy, led by Antonis Samaras, remained the largest party but it fell short of an absolute majority in parliament.
Samaras, as leader of the biggest party, will be tasked with forming a new government by the president, but observers say he will have difficulty forming an administration able to maintain Greece's austerity drive and implement more cuts demanded by the country's creditors.
"We are ready to assume the responsibility of forming a national salvation government with two exclusive goals: to keep the country in the euro and amend the policies of the memorandum," Samaras said late Sunday.
Athens has already committed to finding in June another 11.5 billion euros ($15 billion) in savings in the next two years.
New Democracy obtained about a fifth of support this time, well short of the share needed for an absolute majority in parliament and down from 33.5 percent three years ago.
The other main player Pasok saw its score decimated, polling only 13-14 percent compared to nearly 44 percent in the last elections. The party even looked set to be relegated to third place by the leftist Syriza, which scored 15.5-17.0 percent, more than triple its 4.6 percent of 2009.
"The ruling parties have been struck by an earthquake," shadow foreign minister Panos Panagiotopoulos said on television channel Mega.
Panayotis Petrakis, economics professor at Athens University, expressed hope however that new French president-elect Francois Hollande "would prevent Europe treating us too harshly. There is still a little room for manoeuvre."
Petrakis told AFP that the most likely outcome was another "government of technocrats" headed again by outgoing premier Lucas Papademos, or fresh elections.
Evangelos Venizelos, Pasok leader and the finance minister who negotiated the second bailout, called for a "national unity government" among pro-European parties but admitted this will be "clearly difficult."
Neo-Nazi party Golden Dawn was also set to enter parliament for the first time since the end of the military junta in 1974, with 6.5-7.5 percent, making it the sixth-biggest party in the 300-seat chamber with some 20 lawmakers.
Leader Nikos Michaloliakos said his party would fight against "world usurers" and the "slavery" of an EU-IMF loan agreement he likened to a "dictatorship".
"The time for fear has come," he said.
Independent Greeks, a new right-wing party set up by New Democracy dissident Panos Kammenos, polled around 11 percent to become the fourth-biggest party, followed by the communist KKE on 8.0-9.5 percent.
The Democratic Left, a Europhile new leftist party, notched up 5.5-6.5 percent. In total seven parties were set to enter parliament compared with just five after the last election.
Both Pasok and ND have said they want the "troika" of the European Union, International Monetary Fund and European Central Bank to cut Greece more slack in their two bailout deals worth worth 240 billion euros ($314.0 billion).
But with voters angry at the austerity cuts demanded in response, many of the smaller parties, including possible kingmaker Syriza, want to tear up the agreements.
The communist KKE party want to leave the eurozone and the neo-Nazis say they want to stop servicing Greece's debts, an aim shared by Kammenos who wants to turn to Russia to prop up the country.
"The parties that signed the memorandum (with the EU and the IMF) are now a minority. The public verdict has de-legitimised them," Syriza head Alexis Tsipras said, calling the election a "message of overthrow".
Greece's creditors, not least paymaster-in-chief Germany, the main proponent of austerity before growth, have little appetite to loosen the bailout terms, let alone consider a third rescue.
In ominous comments widely quoted by Greek newspapers on Saturday, German Finance Minister Wolfgang Schaeuble said that if Greece's new government deviated from its commitments, the country would "bear the consequences."
"Membership of the European Union is voluntary," he said in Cologne.