Zac Goldsmith has announced this evening that he’ll be standing as an independent in the Richmond Park by-election he has triggered over Heathrow expansion. The Tories don't seem too alarmed and will not be fielding a candidate against him. This means that the by-election will turn into a fight between Goldsmith and the Liberal Democrats (who held the seat until 2010).
Goldsmith says he is asking his constituents to give him a mandate to continue his fight against Heathrow and that he wants the by-election to be a referendum on a third runway. But the Liberal Democrats will try and turn it into a vote on Brexit. Lib Dems can point out that they too oppose the third runway and that—unlike Goldsmith—they were against leaving the EU. Given that Richmond voted very heavily to Remain (the result for Richmond Borough was 69/31) they will hope that this message resonates.
Last year, Goldsmith won the seat with a 23,000 majority. But his failed London Mayoral campaign and support for Brexit will have taken some of the gloss off him locally. Not to mention the faff of holding another election. The Liberal Democrats will do everything they can to try and regain a seat they held until 2010 and the attitudes to Brexit in this seat do give them a chance. Indeed, William Hill have made the Lib Dems odds-on favourites at 4/6, with Zac at 11/10.
So the Lib Dems have most to lose here. If they can’t win back their old seat in such circumstances, it is hard to see how they will ever be a significant force in UK politics again.