LONDON, ENGLAND - MARCH 30:  Leader of the Labour party Ed Miliband addresses business leaders and members of the media at Bloomberg LP's European headquarters on March 30, 2015 in London, England. Mr Miliband spoke to members of the business community today warning of the dangers of an EU referendum, a conservative party pledge. British Prime Minister David Cameron will visit Queen Elizabeth II at Buckingham Palace today as Parliament dissolves and the parties begin their campaigns ahead of the May 7 general election.  (Photo by Dan Kitwood/Getty Images)