There should be a stealth tax on all private tuition so that all private tutors have to be registered and charge, say, £500 an hour (enough to derter most families) - most of it going back to the treasury. I mean, why should the kids of pushy middle class parents do better in their grades than they ordinarily would have done just because they can afford to pay for extra tuition? People should just accept, if their kids are a bit thick in certain subjects, well, tough.
(btw - kids with autism, other probs etc - Im not including them - they should get all the free extra private tuition they need)