Whigs, Liberals, SDP, and plenty of other parties that eventually disappeared or transmogrified into some other party. I don't know whether the Labour party is close to a break up, but I do think they need to work out who they see as their voters and start talking about policies. Gradually it seems that there's no appetite among the electorate for anything much left of centre, but Labour is still trying to straddle the political spectrum between communists on the left and disaffected Tories on the right.repeatedly hear how one party or another is finished, doesn't happen. They do need to wake up though, the strategy of letting the tories trip over themselves requires the public actually having enough perception to realise and care.
Hartlepool was a terrible result for Labour. More people voted Tory than Labour in the general election. Keir Starmer seems to be watching this dispassionately, like lawyers do when you lose a trial. Lost that one, there'll be a new one next week, etc etc.