FILE - New British Prime Minister David Cameron, right, and Deputy Prime Minister Nick Clegg hold their first joint press conference in the garden of 10 Downing Street in London, May 12, 2010. When Prime Minister Gordon Brown called the general election for May 2010, Labour, which had been in power for 13 years, its longest stretch in government, did better than expected and denied the Conservative Party, now led by the smooth David Cameron, a majority in the House of Commons. Following days of frenzied negotiations, Cameron was able to seal a deal with the centrist Liberal Democrats, to create the first coalition government since the war. (AP Photo/Christopher Furlong, pool, file)
FILE - Britain's Prime Minister Gordon Brown, right, accompanied by wife Sarah, left, announces his resignation as he leaves his official residence at 10 Downing Street in central London, May 11, 2010. When Brown called the general election for May 2010, Labour, which had been in power for 13 years, its longest stretch in government, did better than expected and denied the Conservative Party, now led by the smooth David Cameron, a majority in the House of Commons. (AP Photo/Lefteris Pitarakis, File)
FILE - The leader of Britain's opposition Conservative party David Cameron walks past an image of himself after taking questions following a speech in London, Jan. 4, 2010. When Prime Minister Gordon Brown called the general election for May 2010, Labour, which had been in power for 13 years, its longest stretch in government, did better than expected and denied the Conservative Party, now led by the smooth David Cameron, a majority in the House of Commons. (AP Photo/Matt Dunham, File)
FILE - Conservative Party leader David Cameron gives the thumbs up during a visit to Chester city center, Chester, England, May 4, 2007. When Prime Minister Gordon Brown called the general election for May 2010, Labour, which had been in power for 13 years, its longest stretch in government, did better than expected and denied the Conservative Party, now led by the smooth David Cameron, a majority in the House of Commons. (AP Photo/Dave Thompson, File)
FILE - Britain's new Prime Minister David Cameron and his wife Samantha wave to the media outside 10 Downing Street in London, May 11, 2010. When Prime Minister Gordon Brown called the general election for May 2010, Labour, which had been in power for 13 years, its longest stretch in government, did better than expected and denied the Conservative Party, now led by the smooth David Cameron, a majority in the House of Commons. (AP Photo/Tim Hales, File)