British Prime Minister David Cameron holds a copy of a memo written by ex-Labour minister Liam Byrne and sent to Britain's Chief Secretary of the Treasury in 2010 reading "I'm afraid there is no money" as he speaks during a Conservative Party UK general election campaign event in Norton Sub Hamdon near Yeovil, south west England on April 25, 2015. British Prime Minister David Cameron hit back Sunday at critics who claim his re-election campaign lacks passion, insisting he has the will to win a knife-edge poll on May 7. AFP PHOTO / POOL / TOBY MELVILLE (Photo credit should read TOBY MELVILLE/AFP/Getty Images)
