LONDON, ENGLAND - MAY 10: Former Work and Pensions Secretary Iain Duncan Smith gives a speech entitled 'How the EU has become a force for social injustice' at the 'Vote Leave' campaign headquarters in Westminster on May 10, 2016 in London, England. Britain will vote in a referendum on the June 23 on whether or not to leave the European Union. (Photo by Jack Taylor/Getty Images)
