Downing Street: UK 'to engage constructively' with EU
EU veto: Cameron says he negotiated in 'good faith'
(40 minutes later)
Downing Street has said the UK will "engage constructively" with other EU countries - as David Cameron prepares to explain events in Parliament.
David Cameron has said he "genuinely looked to reach an agreement" on a EU Treaty but vetoed it because it was not in the UK's national interest.
No 10 said they would continue to press for safeguards for the UK's financial services industry.
Mr Cameron told MPs he negotiated in "good faith" and his demands were "modest, reasonable and relevant".
The UK PM vetoed EU treaty changes on Friday, a result his deputy PM Nick Clegg has called "bad for Britain".
The prime minister said he vetoed because he did not secure "sufficient safeguards" on financial regulation.
Labour also criticised the move, but many of Mr Cameron's own Conservative MPs have welcomed what happened.
There is no sign of his pro-European Deputy PM Nick Clegg, who usually sits alongside the PM in the Commons.
Mr Cameron will give a factual account of the decisions he took in his Commons statement at 15:30 GMT, and then face questions from across the House of Commons.
The prime minister is giving an account of the decisions he took in Brussels and will then face questions from across the House of Commons.
Mr Cameron blocked changes to the EU's Lisbon Treaty, which were aimed at addressing the euro crisis and preventing a repeat in the future, at a summit in Brussels on Friday.
'Not easy'
He and Chancellor George Osborne have insisted the veto was in part to protect the City of London from excessive intervention by Europe, but Labour and the UK Independence Party have both argued that actually no additional safeguards were achieved.
No 10 insists the UK will still work closely with other EU countries but deputy prime minister Nick Clegg has said the result was "bad for Britain".
Explaining his decision, Mr Cameron said vetoing the treaty was "not an easy thing to do but it was the right thing to do".
The prime minister insisted the UK was still a "full member" of the EU and would vigorously debate the proposals put forward by the eurozone group.
Mr Cameron blocked changes to the EU's Lisbon Treaty, which were aimed at addressing the euro crisis, at a summit on Friday.
Senior Conservative figures have insisted the veto was in part to protect the City of London from excessive intervention by Europe, but Labour and the UK Independence Party have both argued that actually no additional safeguards were achieved.
The treaty changes needed the support of all 27 EU members, including those not in the euro, such as the UK, to go ahead.
The treaty changes needed the support of all 27 EU members, including those not in the euro, such as the UK, to go ahead.
It now looks likely that all 26 other members of the European Union will agree to a new "accord" setting out tougher budget rules aimed at preventing a repeat of the current eurozone crisis.
It now looks likely that all 26 other members of the European Union will agree to a new "accord" setting out tougher budget rules aimed at preventing a repeat of the current eurozone crisis.
The new accord will hold eurozone members to strict budgetary rules including:
The new accord will hold eurozone members to strict budgetary rules including:
a cap of 0.5% of GDP on countries' annual structural deficits
"automatic consequences" for countries whose public deficit exceeds 3% of GDP
a requirement to submit their national budgets to the European Commission, which will have the power to request that they be revised
a cap of 0.5% of GDP on countries' annual structural deficits
"automatic consequences" for countries whose public deficit exceeds 3% of GDP
a requirement to submit their national budgets to the European Commission, which will have the power to request that they be revised
In an interview with Le Monde on Monday French president Nicholas Sarkozy said he and German Chancellor Angela Merkel "did everything" to let the UK agree to the treaty: "But there are now clearly two Europes.
French President Nicholas Sarkozy has suggested he and German Chancellor Angela Merkel "did everything" to let the UK agree to the treaty but Friday's outcome signalled "there are now clearly two Europes".
"One wants more solidarity between its members and more regulation. The other is attached only to the logic of the single market."
'Self-defeating'
However the deal still has to be agreed by a number of national parliaments, and the reaction of the financial markets suggests it has failed to bring a swift end to the euro crisis.
However the deal still has to be agreed by a number of national parliaments, and the reaction of the financial markets suggests it has failed to bring a swift end to the euro crisis.
The BBC's Rob Cameron in Prague said: "Commentators here have taken a more cautious - and arguably more accurate - view, reflecting the fact that the Czechs haven't signed up to anything yet."
The BBC's Rob Cameron in Prague said: "Commentators here have taken a more cautious - and arguably more accurate - view, reflecting the fact that the Czechs haven't signed up to anything yet."
The current French presidential front-runner, Socialist Francois Hollande, said on Monday that if he was elected next May he would renegotiate the accord, saying: "This accord is not the right answer."
The current French presidential front-runner, Socialist Francois Hollande, said on Monday that if he was elected next May he would renegotiate the accord, saying: "This accord is not the right answer."
One of Chancellor Merkel's close aides in the German parliament told the BBC's Stephen Evans he does not see why "Britain should stay isolated".
One of Chancellor Merkel's close aides in the German parliament told the BBC's Stephen Evans he does not see why "Britain should stay isolated".
CDU Chief Whip Peter Altmaier said: "Over the last years there has been very intensive cooperation between the UK and Germany and I'm deeply convinced that this will continue. It will last. We have so much in common and there are so few issues that divide us."
CDU Chief Whip Peter Altmaier said: "Over the last years there has been very intensive cooperation between the UK and Germany and I'm deeply convinced that this will continue. It will last. We have so much in common and there are so few issues that divide us."
In the UK former Foreign Secretary and Labour MP David Miliband said Mr Cameron's "Churchillian" image of going it alone was misleading.
He told BBC Radio 4's Today programme: "It's a self-defeating way of standing up for Britain. It's a defining moment for Britain and a very dangerous moment. David Cameron has engineered a situation where... Britain is without a say."
'Untenable'
BBC political correspondent Iain Watson says Mr Cameron's decision to veto a new EU treaty without gaining the protection he wanted for Britain's financial services industry has been welcomed by many Conservatives in the Commons.
But Lib Dem backbenchers feel they have been given the green light to criticise Mr Cameron following Nick Clegg's warning about the outcome of the Brussels summit, he added.
Initially Mr Clegg, the Lib Dem leader and Deputy Prime Minister, had said the coalition was united over the use of the veto, but on Sunday he said he had "made it clear" to Mr Cameron it was "untenable" for him to welcome a move that he saw as "bad for Britain".
Mr Clegg blamed French and German "intransigence" and pressure from Eurosceptic Conservatives for putting Mr Cameron in "a very difficult position".
He told the BBC's Andrew Marr programme: "I'm bitterly disappointed by the outcome of last week's summit, precisely because I think now there is a danger that the UK will be isolated and marginalised within the European Union.
"I don't think that's good for jobs, in the City or elsewhere, I don't think it's good for growth or for families up and down the country."
Foreign Secretary William Hague insisted Britain was "not marginalised", and told Sky News that while "everybody knows" that the Tories and Lib Dems had different views on Europe, the negotiating position taken by Mr Cameron had been agreed in advance with Mr Clegg's party.
The criticism from senior Lib Dems - the junior partners in the UK's coalition government - continued on Monday but ex-cabinet minister David Laws insisted the coalition would survive.
The Lib Dem MP told the BBC there was disagreement over the tactical position the UK got itself into, but he insisted that the difficulties were manageable.
He sought to blame France, saying "it seems to many of us that France took a deliberate decision to ignore the quite reasonable demands of the UK, and perhaps actively seek to exclude the UK from the core of European Union countries".
Labour leader Ed Miliband has called on Mr Cameron to use his statement to MPs to "explain why he did something that was so bad for Britain and bad for British jobs".
"He did this because the Eurosceptic wing of the Conservative Party has effectively taken over and that isn't good for the national interest," the Labour leader said.
Lib Dem peer Baroness Tonge has suggested members of her party are reaching the end of their patience with the coalition: "We have just been sold a pup time after time after time," she said.
UKIP leader Nigel Farage said the City was "under very serious threat" of "retribution", adding: "Every time the bond markets twitch, I can see the finger being pointed at those awful Anglo-Saxons in the City of London."
