BRUSSELS, BELGIUM - JULY 20: Chief negotiator for the European Union, Michel Barnier (R) and Secretary of State for Exiting the European Union, David Davis (L) hold a joint press conference during the second round of the Brexit negotiations in Brussels, Belgium on July 20, 2017. (Photo by Dursun Aydemir/Anadolu Agency/Getty Images)
LONDON, UNITED KINGDOM - FEBRUARY 09: British Prime Minister Theresa May attends a press conference with Italian Prime Minister Paolo Gentiloni at No.10 Downing street, London, United Kingdom on February 09, 2017. (Photo by Facundo Arrizabalaga - WPA Pool/Getty Images)
MANCHESTER, ENGLAND - OCTOBER 06: London mayor Boris Johnson waves after speaking to conference on the third day of the Conservative party conference on October 6, 2015 in Manchester, England. The third day of the 2015 autumn conference is being dominated by tough new measures to deal with mass immigration in the Conservative conference speech. (Photo by Dan Kitwood/Getty Images)
LONDON, ENGLAND - MARCH 16: Jacob Rees-Mogg is interviewed in Westminister after British Chancellor of the Exchequer, George Osborne reveals the 2016 budget statement on March 16, 2016 in London, England. Today's budget will set the expenditure of the public sector for the year beginning on April 1st 2016 against the revenues gathered by HM Treasury. (Photo by Ben Pruchnie/Getty Images)
BRUSSELS, BELGIUM - JULY 20: Chief negotiator for the European Union, Michel Barnier (R) and Secretary of State for Exiting the European Union, David Davis (L) hold a joint press conference during the second round of the Brexit negotiations in Brussels, Belgium on July 20, 2017. (Photo by Dursun Aydemir/Anadolu Agency/Getty Images)
