And that concludes our live coverage of a historic night in Greece - the first electoral victory for an anti-austerity party in the eurozone since the start of the crisis in 2008. Follow our news story for further updates.
- Anti-austerity party Syriza is heading for clear victory in Greece's general election, an official projection shows
- Leader Alexis Tsipras says his new government will negotiate a viable financial solution but existing international bailout conditions are over
- Outgoing Prime Minister Antonis Samaras concedes victory
- Syriza may fall just short of 151 seats needed for an outright majority
- Far-right Golden Dawn and centrist The River are set for joint third place - smaller parties will determine if Syriza can govern outright
- All times GMT
- Copyright: Getty Images
With 80% of the vote counted, Syriza is projected to win 149 seats in parliament - two short of a majority.
Podemos, Spain's rising anti-austerity party and an ally of Syriza, has tweeted (in Spanish) to say: "The Greeks are finally going to have a Greek government and not an envoy of Angela Merkel."
UK Prime Minister David Cameron has tweeted to say the Greek election will "increase economic uncertainty across Europe". "That's why the UK must stick to our plan, delivering security at home," he added. The Conservative leader is fighting a general election himself in May.
Nick Barnets, journalist
tweets: #NewDemocracy closed. Not a soul left here at their election pavilion in #Syntagma. #Athens #Greece
Analysts say the eurozone is set for a new bout of volatility, according to AFP.
"A period of uncertainty and heightened market nervousness now seems likely," says Jonathan Loynes of Capital Economics. Unicredit chief economist Erik Nielsen said Greece was in for a "volatile month". While a deal on its debt was still possible, he added, the viability of an anti-austerity government was less certain.
Jerry Siokos in Athens emails: The time of the Left to govern has come. It will be tested fiercely. I don't believe there are plenty of possibilities for any government to change the current situation, therefore I don't feel full of hope. This crisis, in the European South, has mostly affected the youth, and that is why Europe's future is uncertain.
Russell Brand, British comedian and campaigner
tweets: I would vote for Syriza. This is exciting.
Kathimerini, Greek newspaper
tweets: [Greek] President Karolos Papoulias calls Tsipras to congratulate him on victory
With 74% of the vote counted, Syriza has won 36%, followed by New Democracy with 28.1%, the far-right Golden Dawn with 6.3% and The River with 5.9 6%.
The other three parties projected to pass the 3% hurdle to get into parliament are the Greek Communist Party (5.4%), Pasok (4.7%) and Independent Greeks (4.7%).
You can follow the returns live on the Greek interior ministry's website.
If you are just joining us, Greece's anti-austerity party Syriza has won the general election and is set to win 149-151 seats in the 300-seat parliament.Copyright: AFP
It is so far unclear if the party will have an outright majority but leader Alexis Tsipras has praised the vote as an end to the "vicious circle of austerity". Your mandate cancels the international bailouts, he told supporters, but he added that his government would be ready to negotiate a fair, "mutually beneficial solution".
Iraklis Diakos emails: ...Tsipras's party has a difficult road ahead. He has to deal not only with corruption, injustice and poor performance of services in the public sector but also with a widening national deficit and tough creditors with harsh demands.
I just hope for the best for the people of this nation since the measures taken by New Dawn have led to widening the gap between the rich and the poor with unfair and extreme measures for the middle and lower class which led to thrashing the middle class to the grounds.
Belgium's finance minister sees some room to discuss the "modalities" of the Greek debt programme with the other eurozone nations, AP news agency reports.
Johan Van Overtveldt told a Belgian TV channel: "We can talk modalities, we can talk debt restructuring, but the cornerstone that Greece must respect the rules of monetary union, that must stay as it is."
He added: "It is impossible to fundamentally change things."
Yannis emails: I am a 27 year old software engineer from Greece. I am not scared by the election's result but neither do I feel hope. Nothing will change. Greece will just lose six months of reforms. Just like last time a new government will come into power but they won't have any money to spend, so they'll be forced into giving in to EU demands. Mind you I do believe the austerity program is wrong and doesn't make any economic or political sense.
Piers Scholfield, BBC News Athens
tweets: Thousands came from across Europe tonight to express solidarity with SyrizaCopyright: BBC
Hugh Laurie, British actor
tweets: Bravo Syriza! Must feel like they've just won a giant edition of Storage Wars, but let's hope those boxes are full of good stuff. Good luck! [in Greek]
Macropolis, news service, Athens
tweets: Potami [The River, centrist party] leader Theodorakis says slim majority not enough for Syriza, makes it clear he is ready to discuss cooperation
Mehran Khalili, Athens
tweets: "Greek leftists' victory throws down challenge to euro establishment" MT @FT Front page of tomorrow's Financial TimesCopyright: other
Alex Massavetas in Athens emails: There is just one issue and that is economics. Society is quite polarised at the moment. This will be the most difficult elections we have ever had - at least for the last decade. A huge crisis has been ongoing for years and we have been dealing with things we never had to deal with before. There is mass unemployment. I am not sure what to predict., but I am not very optimistic.
Marcus Walker, European economics editor, Wall Street Journal
tweets: Who the Greeks ostracized today: Samaras, Venizelos, Papandreou, Merkel, Schaeuble, troika. But some will be back.
Outgoing Greek Prime Minister Antonis Samaras accepting defeat earlier this evening.Copyright: Reuters
tweets: Cool version of "Rock the Casbah" after Tsipras' speech. Music selections triumphant but cool, no Bella Ciao or punk anthems here.
Chris Morris, BBC Europe correspondent
I wonder if he yet realises what he's done? Pretty historic stuffCopyright: BBC
tweets: #Tsipras is spot on. EU will only return to prosperity if it acts as a positive partnership of equals. Not toddlers at a playground.
Chris Morris, BBC Europe correspondent
tweets: Tsipras wants to assure everyone that he will negotiate. Question is - what will others be prepared to offer him?
Crowd listening to Tsipras - photo by BBC's Piers Scholfield.Copyright: BBC
Tsipras: "You gave this struggle with passion, you gave hope to our people, you defeated fear and you brought a smile to every Greek man and woman. We will struggle with the same passion. Let us raise the sun over Greece. Let us raise the sun of democracy and dignity."
Tsipras: "Our victory is of all the peoples of Europe who are struggling. I would like to assure you the new Greek government will be ready to co-operate and negotiate with our friends, with a just and useful solution so that Greece will return Europe to development and social stability and values like democracy and solidarity.
"In this sincere dialogue, Greece will come with its own proposals, its own national plan of reforms and radical changes with a four-year plan, without shortages, without unrealistic proposals about our debt.
"The new Greek government will prove the Cassandras wrong. No mutual conflict but no continuation of our submission in front of us. We have a great opportunity for a new beginning a new Europe."
Tsipras speaking now - photo by BBC's Piers Scholfield.Copyright: BBC
Asteris Masouras, journalist
tweets: #Tsipras victory speech so far mostly unimpressive, phrases familiar from dozens of speeches in past. Let's hope practice won't be.
Tsipras: "We shall fight all together in order to rebuild our country on new foundations of justice. Because today, friends, citizens of Athens, I address every Greek man and woman. There are no victors or vanquished. Today we defeated the oligarchy. If someone won today, it is Greece, in order to create a new future with dignity."
Tsipras: "Today is a festival. Today we start with hard work... The troika [of international creditors] is over for Greece."
Eyaggelos Lazaridis in Greece emails: I live in Greece I am 41 years old, married with two children. I didn't vote Syriza. I don't believe what they say. In my opinion the next three months will be very difficult. God help us.
Tsipras: "Today the Greek people wrote history. Hope wrote history. The Greek people gave a powerful mandate. Greece is changing the page. Greece leaves behind the poverty of catastrophe, leaves behind five years of suffering."
Syriza leader Alexis Tsipras is taking the stage now in Athens, waving to the crowds under their multi-coloured banners.
The Independent Greeks, a centre-right anti-bailout party led by Panos Kammenos (pictured below, earlier this week), are projected to enter parliament with 4.7% of the vote. The party shares little ideological ground with Syriza but some analysts say its anti-austerity orientation could lead to a deal.Copyright: AP
More than half the votes have been counted. Anti-austerity Syriza has polled 35,89%, conservative New Democracy 28.32%, far-right Golden Dawn 6.37%, centrist The River 5.85%, communist 5.42%, socialist Pasok 4.8% and centre-right Independent Greeks 4.68%.
Omaira Gill, Athens-based journalist
tweets: Here in Athens it feels like we're at the epicentre of an earthquake. Either the landscape will shift or everything will tumble
Macropolis analysis website
tweets: Independent Greeks leader Panos Kammenos makes no mention of coalition in his speech but suggests he's open to cooperation
Golden Dawn, Greece's far-right party, came fifth at the last election in June 2012, taking 6.9%. Despite the continuing detention of its leader, Nikos Michaloliakos, and several other MPs after the murder of an anti-racist musician, its share of the vote is projected to fall only slightly (6.4%) and it should emerge in third place.
Peter Koronaios emails: This was expected, but Syriza will have no easy task fixing things. Europe and the people who funded it are not wiling to let more debt be written off. But it is true that this debt cannot be paid off, certainly not in a depression, it would be hard to pay it off in good times. So what can be done?
Here is Pasok's Evangelos Venizelos voting in Thessaloniki. In the Samaras coalition, he served as deputy prime minister.Copyright: AP
Greek state TV shows crowds in central Athens celebrating Syriza's victory.Copyright: BBC
Outgoing Prime Minister Antonis Samaras is cheered by supporters in Athens after conceding victory in Greece's general election.Copyright: BBC
Samaras (to cheers): "We were obliged to take difficult steps. Mistakes were made but we avoided the worst. Above all I deliver a country that is a member of the EU and the euro. I told the truth to the Greek people to the very end.
"The result is not pleasant for us but it shows that New Democracy is standing up despite the very difficult measures. New Democracy, it seems, lost only two percentage points since the elections in 2012 and will play a very important role as a guarantor of stability and reforms that we need to go forward. I guarantee that I will play a role to the full."
Evangelos Venizelos, head of the socialist party Pasok, has bitterly attacked former Pasok Prime Minister George Papandreou for splitting the socialist vote by fielding his own party. Mr Papandreou had split the party "on a whim", he was quoted as saying by Greek newspaper Kathimerini.
Samaras: "We restored Greece's worth and prestige and set the foundation for development and an exit from the crisis."
Mr Samaras is speaking now live on TV.
Outgoing Prime Minister Antonis Samaras: "The Greek people have spoken and everyone respects their decision."
Mike Chambers in Crete emails: Good news that Syriza are doing well because change is what the Greeks need most. However, Alex Tsipras will have a difficult balancing act to perform. He is correct that austerity measures are not the policies to adopt to correct the economic situation, - but there is a desperate need for deep structural change to get rid of corruption, inefficiency and overmanning.
Chris Morris, BBC Europe correspondent, Athens
This is where Tsipras will make his victory speech.Copyright: BBC
Antonis Samaras, the outgoing prime minister, has phoned Alexis Tsipras to congratulate him on Syriza's victory, Syriza confirms.
Syriza leader Alexis Tsipras being greeted by supporters outside party headquarters in Athens.Copyright: Reuters
If Syriza falls just short of an outright majority, The River (Greek: To Potami) is seen as a potential coalition partner. Formed just last year, The River is centre-left in its outlook but solidly pro-European.
Casting his vote, party leader Stavros Theodorakis (seen below voting in Crete) said Greece seemed to have decided to punish the parties which had led it into the economic crisis, New Democracy and the socialist Pasok. The country now had a chance to put the country on the right course, he added, but he warned against "macho" attitudes.Copyright: Reuters
Marsia in London emails: As a Greek who has been living in the UK since 2004 I am convinced that the Greeks voted with their hearts, not with their minds. Yet, being a Greek and having spent over 20 years of my life in Greece, I know that Greek voters believe in whatever is nicely served to them... including lies and hopeful promises. All that remains to be seen is whether the intuition of the Greek people is right or wrong... They will have my support in any case.
Tony Connelly, Europe editor RTE
tweets: Antonis Samaras, New Democracy leader, has just called to congratulate Alexis Tsipras - Mega TV
With 40% of the vote counted, Syriza is on 35.79% and the conservative New Democracy 28.43%. The far-right Golden Dawn is in third place, followed by new centrist party The River in fourth. The communist KKE, socialist Pasok and centre-right Independent Greeks are also expected to get over the 3% bar to enter parliament.
Jasmine Coleman, BBC News Athens
tweets: Katia, 34, voted for Syriza for the first time this year ''because they want to change the situation and there was no hope"Copyright: BBC
All eyes are now on Alexis Tsipras, the 40-year-old Syriza leader, who is due to speak at 21:00 GMT.
Chris Morris, BBC Europe correspondent Athens
This is a turning point for the eurozone crisis. If you talk to Syriza's economic leaders, they say they have everything costed. But what the party wants is a European debt conference, to look Europe's leaders in the eyes and say, now we have to talk seriously about this.
Mark Lowen, BBC correspondent in Athens
This is a result that will have profound implications and send shock waves far beyond Greece's borders.
Syriza supporters celebrating in Greece's second city, Thessaloniki, a New Democracy stronghold.Copyright: AP
Outgoing Prime Minister Antonis Samaras is expected to make a statement shortly in Athens, with partial results suggesting his conservative New Democracy party has suffered a crushing defeat to Syriza.
Sam Marner in Sheffield emails: The Greeks are a tough people, but they don't suffer fools. Tolerating austerity while the elite are exempt from the same suffering is clearly something they are not prepared to accept, and they are all the better for that.
Imelda Flattery, BBC News Athens
tweets: Definition of knife edge. Syriza needs 151 seats for an absolute majority. Latest projections say 150. (Error margin 149-151)
Nick Malkoutzis, deputy editor of Greek daily Kathimerini English edition
tweets: We now seem to be heading for what opinion polls predicted: Syriza short of majority/with weak one & no obvious allies
Announcing the official projection, Greek electoral official Michael Cariotoglou stressed there was still a margin of error that could lead to a swing of a few seats either way for Syriza. He did not say when the final result would be known.
Syriza's closest rival, New Democracy, is almost nine percentage points behind Syriza but anything less than 151 seats will deny the radical left party an outright victory in parliament. Even with 151 seats, Syriza would be looking for a coalition partner, Greek analysts say.
Another New Democracy figure, Administrative Reform Minister Kyriakos Mitsotakis, has conceded victory, congratulating Syriza and saying its victory "cannot be questioned", AP reports.
"It is evident the Greek people believed there is another way forward than the one described by the government," he said. "For the good of the country, I hope they are right."
First official projection gives anti-austerity party Syriza victory in Greece, with 36.5% of the vote and 149-151 seats in the 300-member parliament.
"It's a really good night, Frau Merkel": banner written in German outside Syriza headquarters in Athens. Photo tweeted by journalist Andres Mourenza.Copyright: Andres Mourenza
Spyros Gkelis, Athens
tweets: I see Left parties of #Portugal #Spain #UK #Ireland and more celebrating #Syriza's victory; unprecedented, at least in #Greece
Far-left Die Linke chair Katja Kipping in Germany
tweets (in German): A beautiful day. A European spring is starting in Greece
Panagiotis Tsantis in Ann Arbor, US emails: In order for Greece to turn the page, many changes to its foreign and domestic policies must occur. There needs to be a strong enforcement of domestic tax policies. No more tax loopholes. Furthermore, the new parliament should focus on how to get businesses to invest in the country as a whole. Greece must focus on marketing their factors of production, so to increase Foreign Direct Investment. Only then will Greece be able to start to recover.
George Papandreou (shown below, after voting in Athens), the former prime minister now leading a new centre-left party called the Movement of Democratic Socialists, has said, "No party, even with a majority, can handle the current situation alone," according to Greek newspaper Kathimerini.
Exit polls suggest his party will fail to clear the threshold for entering parliament. As leader of the socialist party Pasok, Mr Papandreou took power in 2009, when he tried to tackle the economic crisis with austerity measures. He stepped down in 2012 to make way for a short-lived technocratic government under economist Lucas Papademos.Copyright: EPA
Athens-based journalist Nick Barnets
tweets: Alexis Tsipras has arrived at Syriza's campaign HQ.
Initial results have begun coming in. Greece's election commission says after 17.66% of the votes counted, anti-austerity Syriza has polled 35.03%; conservative New Democracy 29.31%; far-right Golden Dawn 6.29%; centrist The River 5.59%, the communist KKE 5.30%; and socialist Pasok 5.21%.
Syriza's manifesto has four "pillars" which include confronting the humanitarian crisis and restarting the Greek economy. But perhaps most significantly it calls for a write-off of the "greater part" of the country's public debt.
Spain's new anti-austerity party, Podemos, has hailed the success of Syriza, seeing it as a precedent for its own electoral chances in the Spanish election later this year.
"Hope is coming, fear is fleeing," said Podemos party leader Pablo Iglesias (below), quoted by AFP news agency. "Syriza, Podemos, we will win."
He told a gathering of about 8,000 party faithful in the eastern city of Valencia: "We are going to be smiling tonight."
Podemos shocked the Spanish political establishment this winter by taking the lead in opinion polls.Copyright: EPA
Roger Dawson in Suffolk, UK emails: The Greek people voted to get rid of the political establishment that got them into the mess in the first place - who can blame them for rejecting the imposition of outdated economics of the 1920s that caused the Great Depression? A 21st Century solution is necessary and now there is hope that it will be found.
So what exactly is Syriza and what does the party's leader Alexis Tsipras stand for?
Two new exit polls based on 100% of the vote suggest Syriza have won 36% or 38% of the vote while New Democracy polled 26% or 28% of the vote. The margin of victory is 10 points, down from 14 points at 17:00 GMT.
New Democracy supporters are watching power slip from the hands of their party after less than three years in office.Copyright: Getty Images
Bill Xenakis emails: Greece, my country, needs all parties support towards a national strategy to increase exports, promote foreign investments with a steady and clear corporate tax law, perform privatisations of public companies with added value to the economy and of course a campaign to all Greeks to change philosophy about tax evasion, social responsibility and value creation.
The smiles say it all: Syriza supporters watch exit polls at the party's campaign tent in Athens.Copyright: AP
Piers Scholfield, BBC News Athens
tweets: Young lady at #Syriza celebration: "this is a new beginning for all of Europe - the end of austerity"
Jasmine Coleman, BBC News, Athens
tweets: More music, more smiles, more cigarette smoke inside #Syriza tentCopyright: BBC
Syriza party spokesman Panos Skourletis says it is clear his party won a "historic victory that sends a message that does not only concern the Greek people, but all European peoples", AP news reports. "There is great relief among all Europeans," he added. "The only question is how big a victory it is."
If you are just joining us, welcome to our live coverage of Greece's general election. A series of exit polls suggests anti-austerity party Syriza has won. The question is whether it can secure 151 seats for an outright majority.
Germany, the eurozone's biggest economic player, is warning Greece it must stick by its bailout commitments. Jens Weidmann, head of the Bundesbank, said he hoped the new government would not make promises the country could not afford, Reuters news agency reports.
"I believe it's also in the interest of the Greek government to do what is necessary to tackle the structural problems there," he told German public broadcaster ARD. "I hope the new government won't call into question what is expected and what has already been achieved."
Konstantinos Tsouparopoulos in Athens emails: The big challenge for Syriza is finding any other credible parties to form a coalition.
Athens-based journalist Omaira Gill
tweets: State TV [channel] Nerit shows that the unemployed voted in huge numbers for #SyrizaCopyright: BBC
"Triumph for euro-horror Tsipras": headline in Germany's biggest circulation tabloid Bild.Copyright: other
Ioanna in Patrae emails: There will be no hero who will save the country from total ruin, we are already there and the way back is certainly going to be long and difficult.
Derek Gatopoulos, Associated Press writer
tweets: One step from conceding: Health Minister Makis Voridis: ""What I see from exit polls is Syriza has won, and we congratulate them"
Soula Bropobsalti in Thessaloniki emails: I am not convinced about the good intentions of the politicians. For example the prime minister said he would do other things but the result was the opposite. He is a liar to me... We have one million unemployed people. Everyone is concerned about their financial security. I want to be part of the European Union but I also want some change in the European Union, with regard to the economy. I want to feel more like I'm in a brotherhood. When voting, I considered jobs, unemployment and public health.
"Hope has won!" - Syriza's first tweet (in Greek) on the results.Copyright: other
Chris Morris, BBC News, Athens
tweets: If exit polls are correct (...IF...) Syriza could form government on its own. Need to watch how many parties cross 3% threshold.
Theopi Skarlatos, journalist, Athens
tweets: Outside Syriza tent an atmosphere of European left solidarity. Hearing more Italian & Spanish than Greek. German Die Linke here too
Mega TV shows flags waving outside Syriza headquarters under the party's slogan, "Hope is on its way".Copyright: BBC
At the Syriza party headquarters, a cheer went up from supporters as the results of the exit polls were announced.
Jasmine Coleman, BBC News, Athens
tweets: Sebastian, 24, Potsdam [Germany] - It's not just a victory for the Greek people but for Europe. It shows there's an alternativeCopyright: BBC
Eric Parks, entrepreneur, Athens
tweets: Low point of the evening: Neo-Nazis outperform opinion polls, battle for 3rd place. A huge - if expected- embarrassment.
Piers Scholfield, BBC News, Athens
tweets: Exit polls suggest v big win for Syriza. But they are only exit polls.
A third exit poll, on Skai TV, gives Syriza 36-39% of the vote and New Democracy 24-27%. That would be a 12-point margin of victory, two points less than the two carried by public TV channel Nerit
People are gathering at the Greek parliament in Athens for the results.Copyright: Getty Images
Here is a guide to the parties contesting the election, from anti-austerity Syriza to the far-right Golden Dawn: Greek elections: Who's who?
@MacroPolis.gr Main exit poll number of MPs Syriza 146-158; New Democracy 65-75; Golden Dawn 17-22; To Potami (The River) 17-22
The River, a new centrist party, and the far-right Golden Dawn came joint third according to both exit polls (6.4% and 8%).
@MacroPolis.gr website estimates that Syriza would win 146-158 seats depending on which exit poll was correct. New Democracy would have 65-75 seats. Remember victory gives the winning party a 50-seat bonus.
The same two exit polls gave New Democracy 23% and 27% respectively.
One exit poll gave Syriza 35.5% and another - 39.5%.
Polls have closed and exit polls suggest Syriza, the opposition leftist alliance which dominated the race, has won by a 14% margin over its closest rival, the conservative New Democracy party.
Welcome to our live coverage of the crucial parliamentary election in Greece, where polls are about to close. Stay with us for news updates, correspondent analysis and comment from readers.