I'm obviously being sarcastic here, but:
How about introducing fees for primary schooling?
A £5000/year fee could be charged with a low-interest government loan meaning it's free at the point of access. This would not deter people from going to primary school, because they would only be paying back their education after earning at least £21 000 per annum. This loan system would in no way prevent poorer people from going to primary school. The debt would be written off once they become pensioners, making it even less significant!
As is argued regarding university fees, why should the rest of society pay so these people can gain education?
Besides, many of these kids go to primary school just for the birthday parties and football, and don't really care about education!
I just can't decide