All of us have seen marriages in which one partner changes while the other stays resolutely the same, and the result is usually unhappy. It will start to matter to a wife that her husband does not hold his knife and fork properly as her friends become smarter, or insists on believing that the Beatles represent the highest form of musical achievement when she has discovered Beethoven and Mozart. So it was with Roy Jenkins and the Labour Party. Even before the Bennite Left made it impossible for Jenkins to stay in that company, he found it embarrassing to hear talk of ‘socialism’, or to be associated with people who would not see the benefits of extending choice or who regarded what we now call the European Union as a bunch of dirty, unpleasant and, quite possibly, criminal foreigners. Such a realisation would be hard enough for someone who had committed a lifetime to the Labour Party and served nearly thirty years as one of its MPs. But Jenkins, the son of a senior union official on a south Wales coalfield who was imprisoned during the General Strike, was more or less born into the party, so for him it should have felt more like an amputation.

That he felt no such thing is one of the overriding impressions that comes from John Campbell’s thoroughly researched biography. Campbell shows a man so sure of his own evolving convictions that it seems more a case of the Labour Party breaking with Jenkins when he chose to go off