Britain's Cameron appeals to EU-reform doubters at home and abroad

Britain's Prime Minister David Cameron delivers a speech on EU reform, at Chatham House in London, Britain November 10, 2015. REUTERS/Kirsty Wigglesworth

LONDON (Reuters) - Britain's prime minister appealed to doubters at home and in other EU capitals on Tuesday to back his attempt to reform the 28-member bloc as a chance to boost prosperity rather than write it off as "Mission Impossible".

David Cameron, under pressure after overseeing what critics see as a lacklustre start to the renegotiation of Britain's ties with the European Union before a referendum, used a speech to offer the most detail yet on where he wants change.