LONDON, ENGLAND - APRIL 09: Demonstrators hold a model pig aloft with an image of David Cameron on it as they gather outside Downing Street on Whitehall on April 9, 2016 in London, England. Hundreds of protesters gathered outside the Prime Ministers residence today calling for Mr Camerons resignation and to protest over his tax dealings that have come to light after the 'Panama Papers' revealed his late father ran an offshore fund which avoided paying tax in Britain for 30 years. (Photo by Dan Kitwood/Getty Images)
