Theresa May must stop "pussyfooting around" and call Sinn Fein's bluff by imposing direct rule on Northern Ireland in a move which will bolster Brexit negotiations, Lord Trimble has said.

Lord Trimble, the former leader of the Ulster Unionist Party and one of the architects of the Good Friday agreement, said that the current situation is "unsustainable".

His intervention comes after the DUP, which props up the Conservative Government in Westminster, refused to agree to Sinn Fin demands to introduce legal protections for the Irish language and said there was "no prospect" of a deal.

The collapse in negotiations threatens to throw the Good Friday agreement into jeopardy and represents a significant blow to the Prime Minister's authority as she tries to finalise a Brexit deal over the Irish border.