A hard Brexit would be unworkable for Ireland and endanger the Northern Ireland peace process, the country’s foreign minister warned on Tuesday night, urging Theresa May to “engage sensitively” with other European states to avoid a destructive Brexit.

“The concept of a ‘hard’ Brexit, with a return to ‘hard’ borders is not something that is either desirable or workable from our perspective, because of the border with Northern Ireland,” Charlie Flanagan told The Telegraph.

He added that the return of a hard border with Northern Ireland threatened to undermine 20 years of normalisation since the end of the Troubles that sees 30,000 border crossings per day.

“The Peace dividend of the “invisible border” cannot be underestimated,” he said.

Speaking ahead of the an all-Ireland Brexit conference in Dublin on Wednesday to discuss the economic and political fallout from Britain’s vote to leave, Mr Flanagan cautioned Britain against taking a confrontational approach with Brussels.