LONDON, ENGLAND - OCTOBER 24: Deputy First Minister of Northern Ireland Martin McGuinness (L) and First Minister of Northern Ireland Arlene Foster speak after a meeting between British Prime Minister Theresa May and the leaders of the three devolved governments at 10 Downing Street on October 24, 2016 in London, England. The Scottish and Welsh leaders want the devolved legislatures and Parliament to all have a vote on Brexit Secretary David Davis's approach. (Photo by Leon Neal/Getty Images)

LONDON, ENGLAND - OCTOBER 24:  Deputy First Minister of Northern Ireland Martin McGuinness (L) and First Minister of Northern Ireland Arlene Foster speak after a meeting between British Prime Minister Theresa May and the leaders of the three devolved governments at 10 Downing Street on October 24, 2016 in London, England.  The Scottish and Welsh leaders want the devolved legislatures and Parliament to all have a vote on Brexit Secretary David Davis's approach.  (Photo by Leon Neal/Getty Images)