Rob Ray
Weight is meaningless
It'd have to be pretty humiliating to get Corbyn to leave, man's more loyal than a beagle and also has a few new leftie MPs to support. A couple of people might flounce, Skinner's in his 80s (I suspect he's only still there to annoy people), I could see him retiring, but not many. Maybe a defection from Richard Burgon, if he's not feeling like having a career?