Media playback is unsupported on your device Media caption German Chancellor Angela Merkel says reform plans must continue in Greece 
 
 Greek conservative Antonis Samaras has three days to form a coalition, faced with EU warnings to keep to the tough terms of international bailouts. 
 
 Two-thirds of Greek voters backed parties opposed to the EU/IMF deal, renewing fears that Athens may default on its debts and leave the eurozone. 
 
 Germany's Angela Merkel has made clear that Greece's reforms must go on. 
 
 But her focus on austerity has taken a knock with the election in France of pro-growth Socialist Francois Hollande. 
 
 Mr Hollande campaigned on a platform of renegotiating the terms of the EU fiscal pact to concentrate more on reviving economic prosperity than simply reducing budget deficits. 
 
 'Utmost importance' 
 
 Analysis New Democracy will try to form an austerity-supporting pro-European coalition government, perhaps with a third party, because it would not gain enough with Pasok to form an absolute majority. But the anti-bailout party Syriza will also try to form an alternative coalition government. There could be a clash of the two - we could be facing fresh elections within weeks. This country is now placed into a period of intense political instability - and by extension the eurozone as a whole. A majority of Greeks have voted against the bailout and against the austerity, which will make it very difficult for the EU or IMF to call for yet more austerity here. The success of the new-right Golden Dawn party indicates how comprehensive a rejection of the political mainstream, the bailout and austerity there has been. The stability and the future of Greece are now in doubt once again. That will bring a lot of dismay to the financial markets and to the eurozone as a whole. 
 
 Mrs Merkel said she would meet France's next president next week "with open arms" but told a news conference that "we in Germany are of the opinion, and so am I personally, that the fiscal pact is not negotiable". 
 
 The German chancellor added that the Greek debt reforms were of "utmost importance". That message was underlined by European Commission spokeswoman Pia Ahrenkilde Hansen, who said Brussels "hopes and expects that the future government of Greece will respect the engagement that Greece has entered into". 
 
 Any political instability in Greece may prompt fresh questions over the country's place in the eurozone. Under Greece's current bailout plan, a further 11bn euros of cuts in spending is due to be found next month. 
 
 News of the Greek vote and the election of Francois Hollande sent the euro falling to its lowest level against the dollar since January. Shares on the Athens stock market tumbled, with the Athex index sliding more than 7% in morning trading. 
 
 Political revolution 
 
 Although a protest vote against the stringent austerity measures enforced on Greeks had been widely expected, in the event the two main parties that had agreed the bailout terms, New Democracy (ND) and socialist Pasok, attracted less than a third of the vote. 
 
 For Greece, it amounts to a political revolution as the country has been run by either one party or the other since the 1970s. Since November, they have been in a coalition, led by technocrat Prime Minister Lucas Papademos, which secured this year's 130bn euro deal. 
 
 Pasok was also in power when Greece negotiated the terms of its 2010 bailout of 110bn euros (£88bn; $143bn). 
 
 New Democracy's support on Sunday slipped from 33.5% to less than 19% of the vote while Pasok's share plummeted from 43% to just over 13%. 
 
 A radical left coalition, Syriza, came second, in front of Pasok, with 16.8% and a party of ultra-nationalists - Golden Dawn - polled almost 7%. 
 
 Having polled the most votes, ND leader Antonis Samaras has begun talks to try to convince other parties to join a new coalition, but only Pasok are so far thought likely to show interest. Pasok's leader and former Finance Minister Evangelos Venizelos has called for a broad coalition government of pro-European parties. 
 
 "A coalition government of the old two-party system would not have sufficient legitimacy or sufficient domestic and international credibility if it would gather a slim majority," he said. 
 
 'Tragedy' 
 
 Allowed only three days to seek a deal by President Karolos Papoulias, the centre-right leader has pledged to keep the country in the euro, although he has promised to try to amend the bailout terms in order to boost growth. 
 
 His first meeting with Syriza leader Alexis Tsipras, the runner-up in the election, came to nothing. 
 
 Mr Tsipras, speaking on Greek TV, said the bailout deal was a "tragedy", and he held out the possibility of a coalition involving "the forces of the left". He has already described the parties that signed the EU/IMF bailout as "de-legitimised" by the public. 
 
 Media playback is unsupported on your device Media caption Greek voters voice their concerns over the instability in the country 
 
 Mr Samaras went on to have talks with Pasok's Evangelos Venizelos. He is also due to talk to Fotis Kouvelis from Democratic Left, who has already made clear his objection to a coalition agreement with Mr Samaras. 
 
 In fourth place were the new right-wing Independent Greeks with 10%. 
 
 Their leader, Panos Kammenos, has already ruled out co-operation with either Pasok or New Democracy, Athens News reported. 
 
 The extremist Golden Dawn party is on course for at least 20 seats in parliament. 
 
 "It is time for those that betray [Greece] to be afraid," its leader Nikolaos Mihaloliakos warned. "We are coming. We are Greeks, nationalists, and we will allow no one to doubt this." 
 
 Deal in doubt 
 
 If Mr Samaras fails to reach a coalition deal, the party in second place, Syriza, can try to form a coalition, and if still unsuccessful, the third party will receive the mandate. 
 
 If still no coalition emerges, Greece will hold another election - a prospect which would alarm the country's international creditors. 
 
 The ability of any new government to carry on with the austerity programme will be crucial for Greece's continued access to bailout funds from the EU, the European Central Bank and the International Monetary Fund - the so-called troika. ||||| Voters in Greece sent tremors across the eurozone on Sunday by recording a massive protest vote against EU-dictated austerity. Parties that had participated in an emergency government tasked with passing deeply unpopular belt-tightening measures in return for rescue loans to prop up the near-bankrupt Greek economy were routed at the ballot box. 
 
 Instead, with the recession-hit country lurching deeper into poverty and despair, voters backed groups on the left and right that had virulently opposed the deficit-reduction policies demanded by international creditors. 
 
 "This is a message of change, a message to Europe that a peaceful revolution has begun," said Alexis Tsipras, who heads Syriza, a coalition of radical left and green groups that took 16.6% of the vote – the second largest share. "German chancellor Angela Merkel has to know that the politics of austerity have suffered a humiliating defeat." 
 
 The reaction from Brussels and the Washington-based International Monetary Fund, which have provided bailouts worth €240bn, was silence. 
 
 With no single party winning enough support to form a government, a period of uncertainty lies ahead as political leaders attempt to form a coalition. Analysts did not rule out fresh elections in June if a new administration cannot be formed. 
 
 The spectre of political unrest and market turmoil prompted many to ask why the elections had taken place at all. 
 
 Voters went out of their way to "punish" mainstream parties widely blamed for years of fiscal mismanagement. "How can we vote for parties to be part of the solution when they got us in this mess in the first place?" asked Poppi Stathera, a mother of two, who said she had been out of work for the past year. "We've been completely destroyed. Our country is in ruins." 
 
 Economic freefall and social disintegration also prompted Greeks to vote for the far right Chrysi Avgi (Golden Dawn), which campaigned on an anti-immigration ticket. The ultra-nationalists, who poured into the streets holding blazing torches, captured 7% of the vote – enough to place 19 deputies in the 300-seat house for the first time since the collapse of military rule in 1974. 
 
 The conservative New Democracy party came in first but with 18.9% of the vote, according to figures released by Greece's interior ministry. 
 
 Pasok, the socialist party led by Evangelos Venizelos, the former finance minister who had been the architect of many of the unpopular policies, won 13.4%, compared to 40% in the last national poll, in 2009. 
 
 "Support for the two main parties literally nosedived in the provinces," said Dimitris Keridis, professor of political science at Athens' Panteion University. "We are talking about a complete collapse of the party system as we have known it, which opens up new concerns about Greece's ability to govern itself." 
 
 In a sign of the political tumult that lies ahead, Antonis Samaras, New Democracy's leader, said he would seek to create a "government of national salvation" that would attempt to amend the loan agreement Greece had signed with its "troika" of creditors, the EU, European Central Bank and IMF. 
 
 "We are ready to assume the responsibility of forming a government of national salvation with two goals," he said, "keeping [Greece] in the euro and amending the policies of the memorandum [outlining the terms of the country's rescue loans] so that there can be development and relief for society." 
 
 Appealing to pro-European forces to consider his offer, he added: "I understand people's rage but our party cannot allow Greece to remain ungoverned." 
 
 If the conservatives are unable to forge consensus, it will fall to Tsipras, as leader of the second biggest party, to try to do so. The leftist leader said he would act on his pre-election pledge to form a government of "the united left", citing his party's spectacular rise in the polls as proof that Greeks wanted such an administration to steer them out of the crisis. 
 
 "With their vote the Greek people have given the mandate for a new day in our country without the cruel bailout measures," he said. "The loan agreement that was signed without their consent has been de-legitimised by popular vote." 
 
 But the spectre of political unrest and market turmoil prompted many to question the snap poll. Athens has been told in no uncertain terms that failure to uphold the conditions of the financial rescue programs will result in a freezing of funds and default. 
 
 "It was a grave mistake to hold this election in such an atmosphere and time of crisis and before the economy was stabilized," said Keridis. "This result couldn't come at a worse time for Greece."
– A long period of instability looms for Greece after voters furious about tough austerity measures gave the two governing parties a hammering at the polls and boosted extremists at both ends of the political spectrum. The Coalition of the Radical Left, which opposes the terms of Greece's bailout, surged to second place with around 17% of the vote while the neo-Nazi Golden Dawn party, which ran on an anti-immigration platform, is poised to enter Parliament for the first time after taking around 7% of the vote, reports the BBC. New Democracy and Pasok, the center-right and center-left parties that had governed in a coalition since last November, saw their support collapse. New Democracy took 19%, down from 33.5% in 2009, and its leader says he aims to form a "government of national salvation." The parties have three days to form a governing coalition but analysts say that Parliament is now so fragmented that a deal may be impossible and new elections will be required. "We are talking about a complete collapse of the party system as we have known it, which opens up new concerns about Greece's ability to govern itself," a professor of political science in Athens tells the Guardian.