BRUSSELS, BELGIUM - DECEMBER 18:  Prime Minister of the United Kingdom, David Cameron speaks to the media after The European Council Meeting In Brussels held at the Justus Lipsius Building on December 18, 2015 in Brussels, Belgium.  European leaders are meeting to discuss David Camerons proposed EU reforms, as well as focussing on the migrant crisis, the fight against terrorism and climate change.  (Photo by Dean Mouhtaropoulos/Getty Images)