As it happened: Greece's big day

Good morning. Welcome to the BBC's live coverage of a big day for Greece. The vote on the austerity measures is currently expected to take place at about 1300 BST (1500 Greek time). We'll have coverage throughout the day as members of parliament take their decisions and members of the public demonstrate against them. We'll be hearing from BBC correspondents in Greece and all over Europe. We'll also have expert analysis and your reaction from around the world. You can contact us via e-mail, text or twitter. We'll publish what we can.

The Associated Press news agency says that only one member of the ruling Greek Socialist party will vote against the measures today, which would mean they would pass.

The Greek government needs to get these measures passed to get the next 12bn euro ($17bn; £11bn) chunk of the 110bn bail-out from the EU and the IMF. Greek central bank governor George Provopoulos is quoted on the front page of the Financial Times as saying a "no" vote would be "suicide" for the country.

If the government wins the vote it's not the end of the story. European economist Megan Greene tells BBC News: "Once it's passed it needs to be implemented and the opposition parties are against this plan, the Greek people are against this plan, even senior members of the ruling party are against this plan, so I think the prospects for its implementation are actually very grim."

The plan they're voting on involves cutting 14.32bn euros ($20.50bn; £12.82bn) of public spending, while raising 14.09bn euros in taxes over five years. Full details of the package are here.

Kit Juckes from Societe Generale says the vote could be as early as 1000 BST.

A vote for the austerity package by the Greek parliament should perhaps be seen not as the moment when Greece avoids default, but as the moment when a default becomes inevitable

More from the AP news agency. The socialist deputy planning to vote against the measures is Alexandros Athanassiadis, but he has said "I will be the only one".

The crowds in Syntagma Square are slightly lower than yesterday. No trouble in the square, but reports of violence at the nearby Olympic stadium.

Reuters is publishing pictures of police clashing with protesters during an anti-austerity rally in Athens, as protesters attempt to block streets leading to the parliament.

The AFP news agency also has pictures of the clashes and says that tear gas has been fired.

The debate in parliament has begun. One of the socialist deputies who was threatening to vote against the measures has told Reuters that, "I have made the decision to vote for the plan because national interests are more important than our own dignity."

If the Greek government were to miss a payment on a bond as it fell due, the immediate impact on the finances of the Greek government would be considerably less than the trauma that such a default would cause for the international banking system. Read Robert Peston's blog.

Many flights at Athens' international Eleftherios Venizelos airport have been cancelled or delayed for a second successive day because of strikes.

Protesters have been urging MPs to reject the package, shouting, "Don't bow your heads, the only way is resistance!"

Elena Panaritis, Greek member of parliament and economic adviser to the prime minister, tells BBC News: "The package is going to go through and we're all very confident."

Groups of people surrounded the car of one member of parliament, Lianna Kanelli, but moved to allow her through when she said she would not vote in favour of the austerity plan.

The vote will be at 1400 local time (1200 BST), according to Elena Panaritis, economic adviser to the Greek prime minister.

Crowds gathering in front of Greek parliament. Many people sporting masks and white face cream to protect them against the almost inevitable volleys of tear gas.

No one in Greece believes the tax increases, lay-offs, privatisations will ever be fully implemented. Read Gavin Hewitt's blog.

Not much sympathy for the protesters from tourists stranded at Athens airport. "We are a little bit disappointed after the strike because it's always the tourists and the people who pay," says Belgian Paul Carleir.

Also at Athen airport, American John Johnson says: "The end result is going to be pointless because Greece is going to have to do what they have to do otherwise it's going to collapse."

writes a comment on the BBC News Facebook wall: If you don't believe cuts are necessary, just see what is happening in Greece, Spain and Portugal, look at their public sector spending and national borrowing

Germany's finance state secretary Joerg Asmussen says the French plan for banks to participate in the second bail-out are a "good foundation for discussion", according to the Sueddeutsche Zeitung. Finance Minister Wolfgang Schaueble will be discussing Greece with financial institutions in Berlin on Thursday.

writes a comment on the BBC News Facebook wall: They need to reject the package. Then they need to leave the EU and have full control over their debts and devalue. They need to leave the EU economic prison and not allow the EU to throw MORE debt and misery onto the country.

It seems very relaxed and calm in the square at the moment, but it was at this time yesterday as well.

Advice from Athens is that the vote will take about an hour to complete, but it is still not certain what time it will begin.

writes on the BBC World Service Facebook wall: Frankly, and meaning no disrespect, Greece shouldn't have been included [in the eurozone] until their figures added up.

comments on the BBC World Service Facebook page: Here's the formula: Get loans, build projects that benefit you and your friends. When it all finally falls apart, force everyone else to pay the bill. Rinse and repeat.

Clouds of tear gas are billowing around the square in front of parliament

A group of demonstrators who were in front of the parliament building suddenly surged at the barricade and I guess they pushed the barricade back about 20 feet at which point a volley of tear gas and stun grenades was fired by the police.

tells the BBC: "I very much fear for the rest of the eurozone. This bail-out mark two is simply going to spread the crisis."

More and more riot police are now streaming out from behind the parliament building, wearing their gas masks, wearing their helmets, carrying their shields and moving into position in front of the parliament building to stop the protesters getting any further.

Anti-austerity protesters have set up roadblocks as they attempt to block streets leading to the parliament

writes on the BBC News Facebook wall: Why can't the Greeks go back to the Drachma?

It's almost like dry ice enveloping the protesters, but this is no theatrical production.

spoke to us: I am out in Syndagma Square, outside the Greek Parliament, as I was yesterday. There are already three or four times the number of people out here today than there was yesterday. I saw some injured people being taken into the metro station on the square, which was serving as a temporary medical unit for protesters mainly overcome by tear gas. Today will be the biggest day of protest yet I think.

writes on the BBC News Facebook wall: Don't blame the Greek public, blame their corrupt politicians that signed over the derivatives.

Protesters have been seen throwing rocks and molotov cocktails.

The anger of the crowd is intense and it's a very different atmosphere from yesterday where you just felt it was skirmishes involving a few hundred anarchists to the disapproval of the trade unionists and other people who were there. This time it feels like the whole crowd feels angry with the police.

spoke to us: I'm on the fence about today's vote. In some ways I want us to default but I know if we don't we are in trouble. I am originally from Nottingham in the UK but have lived in Greece for over 20 years now. I live in Thessaloniki and have joined the locals in many protests here.

The Greek people feel that their MPs are not listening to their voices, but to the EU and IMF.

European stock markets are up about 1.5% as investors anticipate the austerity measures to be passed.

writes on the BBC News Facebook wall: I'm just wondering who's going to buy shares in any Greek company to be privatized and how much those companies are going to be worth under the current circumstances? The new austerity package is so unrealistic.

Dozens of police motorcyclists are taking up positions. I don't know quite what they're going to do. Presumably they're going to come and try to clear the protesters away.

It looks like the crowds are trying to encircle the motorcycles.

How do the police on their bikes push the protesters away?

It looks like the motorcycles are retreating. Now they seem to be driving into the parliament building.

Syntagma Square is a quieter place than it was an hour ago. Police have cleared most of the square, but still the tear gas comes.

Young woman comes up and sprays my face with calamine lotion for free. Efkarfsto poli! Fighting intense but this is diff crowd. Follow Paul on Twitter.

One person here said to me, "There's no positive outcome from this. We've got two choices and both of them lead to bankruptcy."

An "orderly default" seems to be what most commentators think will happen.

What this vote does is it buys everybody a bit of time to basically put in place a solution that minimises the costs of the eventual default.

There are clashes everywhere now. The situation is very critical. I am just 300 metres from the frontline of the clashes. I have had to go into a street just off the square. There is an incredible quantity of tear gas being fired by police. Protesters are retreating and then coming back at the police. Then the police fire more tear gas, and the protesters retreat once more.

People have been trying to loot a nearby McDonald's

See the latest pictures from the Greek riots here.

Greek prime minister tells parliament they must avoid the collapse of the country at all costs and calls for consensus with opposition.

The vote in parliament is due to begin shortly, after being delayed slightly by the violent clashes outside the assembly between police and protesters.

Reuters says the vote in the Greek parliament has begun.

The vote takes place by roll-call. It is done in alphabetical order by constituency. So it's going to take a while for the 300 deputies to vote.

One member of the ruling socialist party has voted against the austerity plan.

Deutsche Bank chief Josef Ackermann says the financial industry would offer European politicians a solution on Greece because a Greek default would be even more dramatic than the Lehman crisis. "I guarantee we will offer the politicians a solution, but this must prevent a meltdown," he told politicians and bankers in Berlin.

writes on the BBC News Facebook wall: Aren't the wrong people protesting? Greeks got themselves into a mess, and now we (the rest of Europe) are having to pay for it... Finland went through an extremely tough depression in the 90s, but we paid all our debt, and blamed no one but ourselves.

Protesters have attacked the offices of the Finance Ministry, off Syntagma Square.

One opposition, conservative deputy has voted in favour of the austerity measures, which means they are likely to be passed.

The problem is the propensity of Greek governments to spend more than they earn and that is a problem that has not been dealt with.

There was a deep rumbling "boo" among protesters in the square when the result was announced over the tannoy system.

says expected euro gains against the US dollar have been fairly muted in reaction to the vote in Greece.

There's a rather disconsolate air. It's as though some air has been let out of the tyres and people are just milling about down on the square. People just realise that this stage of the battle has been lost.

Rebel socialist member Panagiotis Kouroublis' expulsion from the Pasok party reduces the government's seats to 154 in the 300-seat assembly. One deputy from the conservative opposition voted in favour of the government's measures.

Analysts had generally been expecting the vote to be passed but were still relieved when the result came through. "In general we would view it as a positive event. It takes one of the biggest policy issues off the table and turns the sovereign debt focus back to the US and away from Europe," says John Augustine from Third Asset Management in Ohio.

The vote itself is a necessary for everything else. We now need to see the approval for the implementation tomorrow. We would expect to see more support for the opposition on some of the smaller measures.

tweets: Tear gas creating a choking effect across Syntagma Square. How much more of this stuff do the police have in their armoury? A lot, probably

About 30 protesters using ladders have broken into the first floor of an office building on Syntagma Square and attempted to set it on fire, witnesses say.

spoke to us: I was at the protest in the Square. I am now with others in the back streets of Athens chatting about the vote which has been passed. We are annoyed it has been passed but are not that worried as everyone believes it will not be implemented.

Greece has taken "a vital step back - from the very grave scenario of default. This was a vote of national responsibility", the EU says in a statement.

There have been running battles for hours. There are some 500 to 1,000 people involved in these violent protests. You could probably walk 10 minutes in any direction and have a quiet cup of coffee. But there is a broader silent anger - people are furious about what's happening.

If they hadn't voted for this package there would have been some very bad consequences for Greece, but the rest of Europe and possibly the world financial system would have faced consequences. Luckily for them, European politicians haven't had to highlight that there was an international interest in this programme, not just a national one.

We have to formulate a new social contract between the state and its citizens in Greece.

writes on the BBC Business News Facebook page: There is no solution, this is just the best of a very bad bunch.

also comments on Facebook: Lets be frank; The sole purpose of the austerity measures are to (reward) the Greek government and their creditors for their (recklessness and imprudence) and the (common) citizens of Greece will have to "Pick up the tab"

says she is certain the necessary reforms can be pushed through. "I'm just going to remind you that when Mrs Thatcher did reforms, your country took 17 years and very deep unemployment, very deep recession periods. That's what we have to go through if we want to see a different country and have a much more productive economy. Of course we will get that," she tells the BBC's Newshour.

writes on the BBC News Facebook wall: If I was in Athens I might just be trying to storm the parliament. The people are in a no-win situation.

Fires have been lit in the bottom of the Finance Ministry, with the aim presumably that the place will have to be evacuated. Around the square you can hear the stun grenades going off and there is tear gas as well.

The greatest danger facing Greece is not so much default - Greece has actually defaulted twice in the last two centuries and recovered. I think the real danger will be this kind of social collapse. The pictures that we're seeing this afternoon are really disturbing.

With this programme, Greece cements its commitment to redress its economic and budgetary situation. The way is now clear to pay the fifth tranche of bilateral loans from eurozone countries and the IMF.

It is an important step on the one hand for the future of Greece, but on the other hand also for the stability of the euro.

Stock markets seem to have reacted positively to the Greek parliament passing the austerity measures. European shares hit their highest close in two weeks.

You did get a positive [reaction] in the market, [but] what they're looking for is: is there going to be less risk going forward? You've got a sort of relief vote but it could be very short term.

Despite the vote, bookmaker William Hill slashes the odds on Greece defaulting on its debts before the end of 2015 from 1/5 to 1/10.

Let me be optimistic. I'm thinking, for example, that no-one could think that the Olympic Games could succeed in Greece, and it did. Of course it's not the same, but I remind you that Greek people work very, very hard. Greek people cannot afford these austerity measures but there is no alternative for the future of this country.

spoke to us: I have been out protesting a number of times and I still think the worst is yet to come. There are a lot of left-wing activists out protesting now, but a lot of the lower class who will be hit further by these tax cuts will really come out onto the streets now. These cuts will hit people who already don't have much left.

Reuters is reporting that rebel Pasok MP Alexandros Athanasiadis, who had threatened to vote against the government's austerity package, but then decided to vote for it, was attacked as he left the parliament building. Protesters threw bottles and a chair at him and TV images showed him holding his ear, but police sources said he was not injured in the attack.

That's it for our live coverage from Greece for the day. The Greek parliament voted narrowly in favour of a drastic package of austerity measures, needed to win the latest tranche of a 110bn-euro (£98bn) loan from the EU and IMF, which would save the country from defaulting on its debts. But Syntagma Square in Athens was filled with demonstrators and violent clashes continue between protesters and the police.

Thursday will see a second vote in parliament aimed at law reforms that would allow the package to be implemented. Thanks for following our rolling coverage. You can continue to get all the latest news developments via the front page of the BBC News website.