By Daniel Hunter
Lord Lawson, the former chancellor of the exchequer, has said that the UK should leave the European Union.
Writing in The Times, he said British economic gains from an exit "would substantially outweigh the costs".
He predicted any changes achieved by David Cameron's attempts to renegotiate the terms of the UK's relations with the EU would be "inconsequential".
But Downing Street said the prime minister remained "confident" that his strategy "will deliver results".
Mr Cameron is facing calls to bring forward a promised referendum on the UK's EU membership.
He says he will hold a vote early in the next parliament - should the Conservatives win the next general election - but only after renegotiating the terms of the UK's relationship with the EU.
However, Lord Lawson said any such renegotiations would be "inconsequential" as "any powers ceded by the member states to the EU are ceded irrevocably".
Join us on