Inside Theresa May's race to a late-night Brexit deal

After triggering Brexit talks last March, May had a two-year deadline to wrap up a divorce settlement and negotiate the terms of a new free trade agreement before the UK leaves the EU

It was 11 pm Thursday night and the staff Christmas party at 10 Downing Street was in full swing, with karaoke blasting and wine washing down the samosas and sausage rolls.

Downstairs, Prime Minister Theresa May shut herself in her private office with her closest aides. It was time to talk to Arlene Foster again.

The leader of Northern Ireland’s Democratic Unionist Party had been blocking an agreement on what emerged as the thorniest Brexit question of all: what kind of border would divide the British north from Ireland, the European Union nation on the southern part of the island