I don't know about that. If they still continue receiving support - and the outcome here shows they are in fact still popular, almost enough to challenge Labour, - then I don't think it'll be as big of a deal-breaker as some politicians and the media are making it out to be.

Parties work with all sorts of right-wingers and known creeps all over, an anti-Israel/genocide stance will be tolerable. The media will blast it for a while, the main question is only if it'll put them out of contention with the electorate.