LONDON, ENGLAND - NOVEMBER 01: Prime Minister Theresa May attending the the Official Ceremonial Welcome for the Colombian State Visit at Horse Guards Parade on November 1, 2016 in London, England. The President of the Republic of Colombia Juan Manuel Santos and his wife Maria Clemencia Rodriguez de Santos are paying their first State Visit to the UK as official guests of Queen Elizabeth. (Photo by Mark Cuthbert/UK Press via Getty Images)

LONDON, ENGLAND - NOVEMBER 01:  Prime Minister Theresa May attending the the Official Ceremonial Welcome for the Colombian State Visit at Horse Guards Parade on November 1, 2016 in London, England. The President of the Republic of Colombia Juan Manuel Santos and his wife Maria Clemencia Rodriguez de Santos are paying their first State Visit to the UK as official guests of Queen Elizabeth.  (Photo by Mark Cuthbert/UK Press via Getty Images)