It's government policy which has decided this - not Prescott alone, although it is helped by Prescott's apparent dislike for NIMBYs.
If the government does a U-turn on planning policy, they will lose the challenge, and would have to fork out for LDC's costs. Their policy would be in disarray and a complete mess. That would also make them look pretty damn stupid.
Believe me, the Government will back itself to the hilt over this one.