“I am not prepared to go out there and say something that is going to make me look like an idiot five minutes later,” he exclaimed, late Wednesday evening after a long day of talks about new European bank capital rules.

“I am not asking for some UK carve out ... I will not be painted as somehow anti-European, demanding something especially for London," he added.

London is the continent’s biggest financial center, and many UK politicians argue that proposed new laws such as the contentious Financial Transactions Tax would penalize the City more than its European neighbors. There are also disagreements over proposed new bank capital rules – which are seen by many as key to preventing another credit crisis.

The UK is backed by Sweden, which also has a relatively large financial services sector and a traditionally arms-length relationship with the EU.

The UK’s position within the European Union has been increasingly awkward after Prime Minister David Cameron became the only EU leader to veto proposed EU treaty changes in December last year.

With the traditionally less pro-European Conservative Party leading its coalition government, the UK was always likely to negotiate harder with its European neighbors.