David Cameron Speaks At The Conservative Party General Election Rally

CORSHAM, UNITED KINGDOM - MARCH 30: British Prime Minister David Cameron arrives to speak at a rally to mark the start of the general election campaign at Corsham School in Wiltshire on March 30, 2015 in Corsham, England. Campaigning in what is predicted to Britain's closest national election started today, after Queen Elizabeth II dissolved Parliament. (Photo by Matt Cardy/Getty Images)