BRUSSELS, BELGIUM - FEBRUARY 18: British Prime Minister David Cameron meets European Council President Donald Tusk for a bilateral meeting ahead of a European Union leaders summit at the Council of the European Union on February 18, 2016 in Brussels, Belgium. Most of Europe's 28 member state leaders are gathering in Brussels to take part in a crucial summit and vote on British Prime Minister David Cameron's pledge to renegotiate the terms of Britain's membership in the EU, namely proposals to limit benefits for migrant workers. A referendum on whether Great Britain will stay in or leave the European Union is to be held before the end of 2017, though many expect it to take place in June this year. (Photo by Yves Herman - Pool /Getty Images)
