A survey by ICM for the Foreign Office has revealed widespread ignorance about the EU.

The survey found that one in 15 Britons believed the United States to be a member of the European Union, while only 75 per cent knew that Britain was a member. However, the more that the public found out about Europe, the more enthusiastic they were.

The Foreign Office was accused of asking biased questions after the poll suggested that opposition to joining the euro (at 47 per cent) was far less entrenched than other surveys.

Dominic Cummings of Business for Sterling said: "Opposition is about 60:25 and has strengthened since September 11."