VALLETTA, MALTA - NOVEMBER 11: British Home Secretary Theresa May, shoe detail, receives a tour of HMS Bulwark during the Valletta Summit on migration on November 11, 2015 in Valletta, Malta. The Summit will bring together representatives from the European Union and African countries to address the challenges and opportunities of the largest migration of people to Europe since World War II. (Photo by Ben Pruchnie/Getty Images)

VALLETTA, MALTA - NOVEMBER 11: British Home Secretary Theresa May, shoe detail, receives a tour of HMS Bulwark during the Valletta Summit on migration on November 11, 2015 in Valletta, Malta. The Summit will bring together representatives from the European Union and African countries to address the challenges and opportunities of the largest migration of people to Europe since World War II.  (Photo by Ben Pruchnie/Getty Images)

British Home Secretary Theresa May's shoes are pictured as she addresses media personnel outside the Cabinet Office in London on June 28, 2015, following a COBRA meeting. The British government cautioned Sunday that other attacks 'are possible' in Tunisia after the mass shooting two days ago that left 38 people dead including at least 15 Britons. AFP PHOTO / NIKLAS HALLE'N (Photo credit should read NIKLAS HALLE'N/AFP/Getty Images)

British Home Secretary Theresa May's shoes are pictured as she addresses media personnel outside the Cabinet Office in London on June 28, 2015, following a COBRA meeting. The British government cautioned Sunday that other attacks 'are possible' in Tunisia after the mass shooting two days ago that left 38 people dead including at least 15 Britons. AFP PHOTO / NIKLAS HALLE'N        (Photo credit should read NIKLAS HALLE'N/AFP/Getty Images)

BIRMINGHAM, ENGLAND - OCTOBER 02: The shoes worn by British Prime Minister Theresa May as she delivered a speech about Brexit on the first day of the Conservative Party Conference 2016 at the ICC Birmingham on October 2, 2016 in Birmingham, England. On the opening day of the annual party conference, British Prime Minister Theresa May has confirmed that the deadline for triggering Article 50 of the Lisbon Treaty to will be the end of March 2017. (Photo by Matt Cardy/Getty Images)

BIRMINGHAM, ENGLAND - OCTOBER 02:  The shoes worn by British Prime Minister Theresa May as she delivered a speech about Brexit on the first day of the Conservative Party Conference 2016 at the ICC Birmingham on October 2, 2016 in Birmingham, England. On the opening day of the annual party conference, British Prime Minister Theresa May has confirmed that the deadline for triggering Article 50 of the Lisbon Treaty to will be the end of March 2017.  (Photo by Matt Cardy/Getty Images)

BOURNEMOUTH, ENGLAND - MAY 20: The Home Secretary, Theresa May, Shoe Detail, addresses officers at the Police Federation annual conference on May 20, 2015 in Bournemouth, England. In her first speech since being reappointed Home Secretary, Mrs May said she wanted to stop the 'tick box culture' of policing and warned officers to 'stop crying wolf' as she spoke at the Bournemouth International Conference centre. (Photo by Matt Cardy/Getty Images)

BOURNEMOUTH, ENGLAND - MAY 20:  The Home Secretary, Theresa May, Shoe Detail, addresses officers at the Police Federation annual conference on May 20, 2015 in Bournemouth, England. In her first speech since being reappointed Home Secretary, Mrs May said she wanted to stop the 'tick box culture' of policing and warned officers to 'stop crying wolf' as she spoke at the Bournemouth International Conference centre.  (Photo by Matt Cardy/Getty Images)

A picture shows the shoes of British Prime Minister Theresa May (C) as she visits a construction site where new HSBC offices are being built in Birmingham, central England, on October 3, 2016 on the second day of the annual Conservative Party conference. British Prime Minister Theresa May announced on Sunday that her government will trigger Brexit negotiations by the end of March, putting the country on course to leave the European Union by early 2019. / AFP / POOL / Stefan Rousseau (Photo credit should read STEFAN ROUSSEAU/AFP/Getty Images)

A picture shows the shoes of British Prime Minister Theresa May (C) as she visits a construction site where new HSBC offices are being built in Birmingham, central England, on October 3, 2016 on the second day of the annual Conservative Party conference.
British Prime Minister Theresa May announced on Sunday that her government will trigger Brexit negotiations by the end of March, putting the country on course to leave the European Union by early 2019. / AFP / POOL / Stefan Rousseau        (Photo credit should read STEFAN ROUSSEAU/AFP/Getty Images)