LONDON, ENGLAND - DECEMBER 14: British Prime Minister Theresa May attends The Sun Military Awards at The Guildhall on December 14, 2016 in London, England. (Photo by Samir Hussein/Samir Hussein/WireImage)

LONDON, ENGLAND - MARCH 13: British Prime Minister Theresa May attends Commonwealth day celebrations service and reception at Westminster Abbey on March 13, 2017 in London, England. (Photo by Samir Hussein/WireImage)

LONDON, ENGLAND - JULY 12: Prime Minister Theresa May at the official welcome ceremony on Horseguards Parade during a State visit by the King and Queen of Spain on July 12, 2017 in London, England. This is the first state visit by the current King Felipe and Queen Letizia, the last being in 1986 with King Juan Carlos and Queen Sofia. (Photo by Mark Cuthbert/UK Press via Getty Images)

Prime Minister Theresa May arrives at the Menin Gate in Ypres ahead of the Passchendaele commemoration service. (Photo by Yui Mok/PA Images via Getty Images)

LONDON, ENGLAND - NOVEMBER 12: Prime Minister Theresa May during the annual Remembrance Sunday memorial on November 12, 2017 in London, England. The Prince of Wales, senior politicians, including the British Prime Minister and representatives from the armed forces pay tribute to those who have suffered or died at war. (Photo by Chris Jackson/Getty Images)

LONDON, ENGLAND - JULY 10: British Prime Minister Theresa May leaves following a cabinet meeting at 10 Downing Street, on July 10, 2018 in London, England. Ministers are meeting for a cabinet meeting after the Prime Minister was forced to carry out a reshuffle following the high profile resignations of Boris Johnson and David Davis over her controversial Brexit strategy. (Photo by Jack Taylor/Getty Images)

LONDON, ENGLAND - MARCH 11: Prime Minister Theresa May attends the Commonwealth Service on Commonwealth Day at Westminster Abbey on March 11, 2019 in London, England. The Commonwealth represents 53 countries and almost 2.4 billion people and 2019 marks the 70th anniversary of the modern Commonwealth, enabling cooperation towards social, political and economic development. (Photo by Chris Jackson/Getty Images)

PORTSMOUTH, ENGLAND - JUNE 05: British Prime Minister Theresa May attends the D-day 75 Commemorations on June 05, 2019 in Portsmouth, England. The political heads of 16 countries involved in World War II joined Her Majesty, The Queen on the UK south coast for a service to commemorate the 75th anniversary of D-Day. Overnight it was announced that all 16 had signed an historic proclamation of peace to ensure the horrors of the Second World War are never repeated. The text has been agreed by Australia, Belgium, Canada, Czech Republic, Denmark, France, Germany, Greece, Luxembourg, Netherlands, Norway, New Zealand, Poland, Slovakia, the United Kingdom and the United States of America. (Photo by Jeff J Mitchell/Getty Images)