Nine years ago on a train I had a chance but lengthy conversation with Tony Blair about Europe. He concluded: “The thing is, you have to get in there, be as constructive as possible, and they will come round to our way of thinking.” I was astonished by this apparent naivety and replied: “and replied: “I have seen this film before and I know the ending.”

I hope the UK prime minister will forgive me for my breaking this confidence. But I want to say that I was wrong. His The recent poisonous exchanges with Jacques Chirac may sound like previous British failed attempts at constructive engagement in Europe. But this film is different and has not yet ended.