They're still there, that's the problem.
I think it's time for the Labour party to go out to pasture. There needs to be a split, take some Conservatives, some UKIP (maybe, if there's any more moderate ones left) but enough to lose the baggage of any one party, lose the extremes and head for the middle ground.
Unless that happens (and it seems at this point it won't) I don't see there being an effective opposition anytime soon.