EU leaders poised to line up 26-1 in support of Franco-German blueprint, but PM had apparent blessing of Nick Clegg rejected the invitation. After the deed was done, some leaders didn't want to shake his hand. French President Nicolas Sarkozy walked right by him, as if he wasn't there.

The others balked, France most vocally, accusing Cameron of putting Britain's perceived interests ahead of resolving the EU's worst crisis. As the result of this, it seems that David Cameron, the British prime minister, had become Europe's outcast. Rejecting an invitation to join 26 European partners in a tighter financial alliance to save the euro, making Britain odd man out at a time of deep financial peril, and raising doubts about whether Britain can realistically remain a member of the European Union.

Former British Europe minister Denis MacShane, a House of Commons legislator and longtime advocate of closer ties, said the sudden break with the other 26 countries means Britain's role in the European Union is effectively over.

"There is now little point in Britain staying in the EU," said MacShane, who was a minister in Tony Blair's generally pro-Europe Labour Party government. "It is an historic turning point and Britain might as well get out now, as Europe's future will be settled without us."

EU leaders promptly agreed to bypass Britain and establish a new accord on the euro among themselves by March. The EU appeared poised to line up 26-1 against Cameron in support of the Franco-German blueprint, leaving Britain utterly isolated.

Cameron's bombshell came at what was billed as the most important EU summit in years, with the fate of the single currency hanging in the balance. The veto was unexpected and was being seen as a watershed in Britain's fractious relationship with the rest of Europe. Cameron insisted on securing concessions on, and exemptions from, EU financial markets regulation as the price of his assent to the German-led euro salvation blueprint.

But Sharon Bowles, the Lib Dem MEP who chairs the European parliament's influential monetary affairs committee, accused Cameron of betraying British interests to curry favour with Tory Eurosceptics.

"The way in which the UK is isolated now is very damaging. We played, we lost, and now we are worse off," she told the BBC. "The point of the summit in Brussels was to fix the eurozone. However, under pressure from Eurosceptics in his party, Cameron has decided effectively to relegate the UK to the sidelines of Europe … Without a place at the negotiating table, we may not get to influence those very policies that will impact on the City and our financial sector as a whole."