Can MPs really defect? 

‘He did it years before William Donaldson did The Henry Root Letters,’ said my husband querulously, as though I had accused him on peak-time television of saying the opposite.

The ‘he’ in question was Humphry Berkeley, who as a Cambridge undergraduate just after the second world war pursued an elaborate hoax by assuming the identity of a fictional public school headmaster, Rochester Sneath, to write embarrassing letters to the famous, eliciting risible replies. The collection was not published until 1974. The Henry Root Letters were published in 1980.

Berkeley wrote another book about leaving the Conservatives and joining Labour, published in 1972. It was called Crossing the Floor. The title was misleading because the phrase refers to MPs who move over to the opposing benches, and Berkeley had already lost his seat, in 1966 – partly, it was said, because the electors of Lancaster did not care for his prominent attempt to decriminalise homosexual acts.