They say the darkest hour is the one before dawn but for Theresa May it came at lunchtime on Monday when the deal she had sought to negotiate with Brussels and Dublin unravelled over a lunch of turbot in Jean-Claude Juncker’s office. It was a little after 1.30pm UK time when the wording of an agreement to prevent a hard border between Northern Ireland and the republic — painstakingly thrashed out last weekend — imploded after opposition from the DUP, the hardline Ulster Protestants whose 10 MPs are all that separates May from defeat in the House of Commons.

In part, it was a comedy of errors. The draft of the document which was leaked to the Irish broadcaster RTE at 12.16pm Brussels time, suggesting