BOLTON, ENGLAND - APRIL 8:  Britain's Prime Minister David Cameron reads a book to Lucy Howarth, 6, and Joshua Davies, 5, during a visit to Sacred Heart RC primary school in Westhoughton on April 8, 2015 near Bolton, England. Britain goes to the polls in a General Election on May 7. (Photo by Kirsty Wigglesworth - WPA Pool/Getty Images)