In the latest twist in his uncomfortable political career Zac Holdsmith has resigned as an MP to fight a by-election in his Richmond-on-Thames constituency, supposedly in protest at the government's decision to back a new runway at Heathrow. This, he thinks, will provide a referendum for local people on the issue. He will stand as in independent.
His intention had been long trailed. It took very little time for the Conservatives to say they would not contest the seat. This leaves him as the Conservative candidate by default. It also means that the chance that there will be a pro-Heathrow candidate is incredibly low. That means his gesture is an empty folly.
If Labour was wise it would treat it as such. That's firstly because it has no hope of winning the seat.
It's secondly because if it sat the by-election out there has to be a chance that the Lib Dems will win in a poll that would then be a referendum in the government's handling of Brexit, which will have been deeply unpopular in wealthy south-west London.
So that would be one less for the government majority and a mighty blow for the man who ran a very nasty and racist campaign to be Mayor of London.
But will Labour have the sense to sit it out? I can only hope, but without expectation. Tribalism matters to Labour more than the overall political good. And that is a loss to us all.