Attacks on the European Union will reduce Britain's influence in Brussels, business leaders have been warned.

Pat Cox, president of the European Parliament, accused CBI director general Digby Jones and chancellor Gordon Brown of promoting "chauvinistic propaganda" against economic reforms.

"Anyone who regards themselves as pro-European should refrain from encouraging fantasies and misconceptions about Europe for short-term tactical or personal reasons," he told the CBI's annual conference.

"I would urge British political leaders to rise above the daily diet of scary kites flown about EU superstates, tax harmonisation and floods of immigrants."

Jones has attacked the European Commission for failing to take business interests into account.

Gordon Brown has claimed that a slow pace of economic liberalisation elsewhere in the EU could undermine Britain's economic performance.

"I congratulate Britain for the economic success it has achieved but. Britain does not have a monopoly on the economics of reform," Cox added.

"It is not correct to portray Britain as being isolated on economic reform."