The Walton by-election, in Liverpool, took place in July 1991, twenty years ago. It arose after the sudden death of Eric Heffer, the left-wing Labour MP for Walton. At the time it created quite a political stir. It was also a key factor in the demise of the Militant, which had boasted it could win the seat, but failed miserably. The whole episode played into the hands of Labour’s right wing that used it to expel Militant from the Labour Party. To understand what happened we need to take a brief look at the background.