LONDON, ENGLAND - APRIL 06: British Prime Minister, Theresa May, greets The President of the European Council, Donald Tusk to 10 Downing Street on April 6, 2017 in London, England. Donald Tusk is meeting Theresa May ahead of the EU27 leaders' meeting on Brexit on April 29, 2017 in Brussels. (Photo by Dan Kitwood/Getty Images)