‘Gladstone spent his declining years trying to guess the answer to the Irish question; unfortunately, whenever he was getting warm, the Irish secretly changed the question.” This Sellar and Yeatman classic from 1066 And All That is just what Michel Barnier, the European Union’s chief negotiator, has done to the United Kingdom of Great Britain and Northern Ireland. Today, Theresa May will speak and her task is to change the Irish question.

Mrs May has arrived at the point at which the contradictions of her position are starting to bite. Ruling out membership of the single market meant a choice between a trade deal with Europe or a form of customs union. One was ruled out because it meant a hard border with Ireland; the