This is emotive stuff, which really gets to the nuts and bolts of the issue, so lets all try to stay calm and respectful. I'd like to post a few facts, to try and help both sides understand the other's perspective.
Canon Law 793 states that:
"Catholic parents have ... the duty and the right to choose those means and institutes which, in their local circumstances, can best promote the catholic education of their children. §2 Parents have moreover the right to avail themselves of that assistance from civil society which they need to provide a catholic education for their children."
However, this is not English Law, so does not directly equate to a right to a Catholic School.
The First Protocol, Article 2 of the Human Rights Act 1998, Part 2, states that:
"No person shall be denied the right to education. In the exercise of any functions which it assumes in relation to education and teaching, the state shall respect the right of parents to ensure such education and teaching in conformity with their own religious and philosophical convictions."
However Amnesty International UK, in Amnesty (September - October 2000), reportedly stated:
"This article guarantees people the right to access to existing educational institutions; it does not require the government to establish or fund a particular type of education. The requirement to respect parents' convictions is intended to prevent indoctrination by the state. However schools can teach about religion and philosophy if they do so in an objective, critical, and pluralistic manner."
I say "reportedly stated" because I can't find a link to the original source to verify it, but it is widely quoted on the internet.
Nevertheless there is a strong tradition of Faith Schools in this country, for historical reasons. While people still want them, they are likely to continue (and the current and previous government have encouraged them). In my view that's acceptable, so long as they are recognised as a privelege rather than a right. People also need to recognise that in difficult economic times, priveleges are in short supply, and will cause controversy if they are handed out without consultation with the wider community.