A majority of business leaders believe the EU is "failing", according to an ICM poll.

Of the 1,000 company chief executives interviewed, just 18 per cent believed that the proposed European constitution would be good for their businesses, while 59 per cent said it would be bad and 23 per cent did not know.

The survey was commissioned by the euro-sceptic New Frontiers Foundation.

The results came as foreign secretary Jack Straw was accused of trying to add more "red lines" to Britain's negotiating stance on the constitution.