Britain will not accept the European single market being discussed by any group other than the full 27 members of the European Union, British prime minister David Cameron said today.

"Why are we in the organisation? We're there because we're a trading nation, and we want access to the single market and a full say about the rules of the single market," Mr Cameron told BBC Radio 4.

"What we can't have is the single market being discussed outside the European Union, and we'll do everything possible to make sure that doesn't happen," he added.

Mr Cameron's comments come amid fears that groups within the EU that do not include Britain could decide new rules affecting the single market as they try to ease the euro zone debt crisis.

Britain was left isolated in December when Mr Cameron refused to sign up to a new EU treaty to tackle the crisis.

The British prime minister also hailed what he said was a big fall in bonuses to bankers and other professionals, which have stoked public anger at a time of deep government spending cuts.

"There's been a massive reduction in the level of bonuses compared with three or four years ago .... and we want to see that trend continue."