I think it's worth pointing out that for Catholic schools at least, a large percentage of Sunday's offertory donations go towards the diocesan schools fund - in my parents' small parish (of mainly elderly churchgoers) it's around 40% of Sunday's takings, so those who are active Catholics (rather than those who just pay lip service
) are paying twice - once through taxes and a significant amount through their Sunday donations.
If you really don't like the fact that there are faith schools, then set up a Free School in your area. Having done it, it isn't for the fainthearted, but it means that you can (within reason) have the school that you want, without the 'unfairness' of the religious question.
[For the record, I am Catholic, but we've now moved from SW London. In the town we now live in, there are only three non-faith primary schools - all of the rest are CofE with one Catholic primary. ALL of the schools are oversubscribed - the CofE ones don't discriminate on religious grounds - it's purely distance - and for the best ones, the house prices are eyewatering, so it's still discriminatory - just on your purse, not your beliefs. FWIW, the Catholic primary takes a % of non-Catholic children so it's not purely for those who are in church on Sunday or arranging flowers.