You elect a leader because of the policies he stands for. It's up to him t use his mandate to ensure those policies are adopted by the party. You've got to assume that if you're a labour MP and you stand up and say you're against the key policies he's promoting then you won't be in the shadow...
I'm not sure about that. He got nearly 60% of the vote so has a strong mandate for his policies (assuming he doesn't change half of them now he's in and the realisation sets in). There is now most definitely "clear blue water" between the two main parties and they've got nearly 5 years to...