When the by-election was held in Batley and Spen to return an MP to replace Jo Cox after her murder five years ago, the main parties refused to contest it, allowing Tracy Brabin, the Labour Party candidate, a free run. Although nine fringe candidates stood in the by-election, Ms Brabin was elected with 86 per cent of the vote.
This was an innovation. On the previous occasion an MP was murdered – Ian Gow, the Conservative MP, was killed by an IRA car bomb in 1990 – the main parties fought the ensuing by-election in Eastbourne, and it was won by David Bellotti, the Liberal Democrat. The time before that, in the Enfield Southgate by-election of 1984, after Sir Anthony Berry, the Conservative MP, was killed by the Brighton bomb, fellow Conservative Michael Portillo was elected to replace him in a three-cornered contest.
It could be argued that a vigorous democratic contest is the best reply to the anti-democratic violence of those who kill elected representatives – as a kind of morality play, acting out how a free and peaceful society resolves its differences.