People generally don't like that sort of behaviour and tend to react - Libdems out after their coalition with the Conservatives and all that followed; and my local MP ousted by an independent for paying so little attention to a rampant local concern. I'm sure there are other examples that I can't remember right now. 😂
Big risk.
If by "that sort of behaviour" you mean the sitting MP deliberately standing down so that a big name with big ambitions can be parachuted into parliament, then they may not like it. In my scenario, that is what Starmer is banking on, secretly wanting Burnham to lose (which is why he "backs" him)! However, the media and the Burnham machine will throw a lot of mud at the local Reform bloke, some of which will stick, and with Restore already on seven percent, chipping away at Reform from the right, Burnham could still win, unless the Greens get their act together and attack from the left!
!ALIVE
!BBH
I mean there are different ways of looking at it: you could have a view which is "by any means necessary", but generally speaking, I don't think people like feeling they're being used.