Harpsi - duh? Because non-catholics wouldn't be practising catholics, which is the ethos of the school! Although Muslims, in practising a faith, would find much more in common with the school ethos than, say, someone who practices no faith and despises those who do. I know Hindu families who have their children at a catholic school and they are very happy with it. If we lived in Tower Hamlets and had no access to a Catholic school, I'd be very happy for the kiddies to go to one of the local muslim schools, ditto Jewish schools etc, as they would still have the strong sense of community and moral principles that their current school does. I rather they went to another faith school, than a school which doesn't teach those strong principles.
Drosophila - I think you'll find that Catholic schools have changed a lot since we were at school. Similarly, Catholic parents have changed too - there are as many liberal Catholics as there are liberal Jews, liberal muslims etc. We don't all agree with the Pope on everything. In fact neither does my Priest!
Kaz - please could you present sound evidence to support your point that faith schools are another tool used by the middle classes? Faith schools are based on faith, not catchment area. My orthodox Jewish neighbour drives 12 miles each way to take her sons to an orthodox Jewish school in North London. Catholic schools are generally populated by Irish working class children, with smatterings of Spanish, Polish etc. Where is the evidence to support your point?
I agree middle class families know how to work the system, but that applies more to catchment areas, where many people use false addresses to access a place at a good school.