Given that the media narrative was all about how much the Tories would win by, rather than whether they would win, then this seems to be a sizeable boost to Labour and a blow to the Tories.
The Tories have now failed to win two by-elections where they were overwhelming favourites right up to polling day.
I think in B&S the Tories were approx. 80% favourites in the betting to win going into polling day. In Chesham and Amersham the Tories were even greater favourites in the betting running up to the polling.
Something going on?
Clearly there's lots going on. There is obviously at least some idea of a 'progressive alliance' at least with voters.
Though I think we should add Hartlepool into the mix in trying to understand things because no matter what over the three by elections in England this year, it is not a good story for Labour. Big loss in Hartlepool, worst ever by election in C&A, and a hold in B&S with a much reduced majority.
B&S has its own wrinkle in the grifting shyster that is Galloway. Particularly in that the polling that suggesting a Tory win, he was on 6% of the vote, and he actually got 20%. That looks like he took votes from both the Tories and Labour, and I don't think it's easy to say that it's mainly Labour votes, or that those which might once been Labour will go back to Labour since Hartlepool is much more like B&S than C&A is.
Also for B&S, there seems likely to have been a Hancock factor. Where those votes that were Hancocked went it's difficult to say.
I have to say I am very glad no matter what that Kim Leadbeater and Labour won here. Had she/they lost then it really would have been disastrous for opposition to the Tory govt. It means that we have probably avoided another leadership contest in Labour though Starmer needs to get better at having an effect quickly.