Opponents of the council’s proposed new Catholic school will get their day in court.

Judge Ockleton said the British Humanist Association (BHA) and the Richmond Inclusive Schools Campaign (Risc) should be allowed to challenge Richmond Council’s plans for the site in Clifden Road, Twickenham.

The BHA, whose supporters include comedian Stephen Fry and author Salman Rushdie, said the case could have huge national implications.

Campaigners claimed the Government’s new Education Act meant the council first had to consider proposals for an academy or free school, which can only enrol a maximum of 50 per cent of pupils based on their religion.

Lord True, leader of Richmond Council, said he was disappointed by the High Court’s decision to grant a judicial review, which will look into whether the authority acted lawfully when it approved the Diocese of Westminster’s plans for a new Catholic primary and secondary school on May 24.

He said the council’s own survey found 67 per cent of parents and residents supported the move.

Lord True said: “I am disappointed that despite the clear, democratic decision that has been taken by our community, the national BHA and its local acolyte, have moved forward with their campaign.

“This delay and uncertainty will also be of huge concern to a large number of parents who have already started applying for places for their children at either of the schools.”

The council’s plan for a new Catholic school, which would prioritise admissions to children from Catholic families, has sparked huge controversy amid concerns over a shortage of classroom places across the borough.

Jeremy Rodell, spokesman for Risc, vowed to push ahead with the legal battle as long as it can secure a limit on court costs.

He said: “That’s good news for the thousands of people in the borough who think that it’s wrong to use the only currently available site for a state-funded school that can turn away local children simply because of their parents’ beliefs, especially when there’s so much competition for high quality secondary school places.”

He also hit back at Lord True’s claims that members of Risc were acolytes of the BHA. 

He said: “Lord True knows full well that Risc supporters come from right across the spectrum, even including some Catholics.

“Most supporters don’t care about religion or humanism but simply want good schools open to all.”

The BHA said the hearing –expected to start in October – will be the first case in which campaigners have legally challenged a proposed faith school because of religious discrimination.

Andrew Copson, chief executive of the BHA, said: “When proposing to establish new state-funded schools, religious groups largely avoid competition with other proposals and instead usually arrange directly with councils to open schools ‘by the back door’, leaving the public with no other choices.

“When such an arrangement has been reached, proposed faith schools have had a 100 per cent success rate in subsequently opening.

“It is time to challenge this practice and attempt to redress the imbalance in the routes through which faith schools and other schools can open.”

Lord True said the High Court case would come at a huge cost to taxpayers in Richmond.

He added: “As I have said before, the council will defend our local decision against legal action confidently and vigorously, seeking to recoup any costs.”