Faith Groups are being allowed to open new schools by the "back door" by circumventing rules designed to encourage competition from other providers, according to research from campaigners.
Church of England, Catholic and Muslim schools are among those that have received "preferential treatment", with ministers giving the green light to 16 new schools without considering bids from non-religious organisations, the British Humanist Association (BHA) said.
Laws introduced five years ago were supposed to ensure that faith groups, academy chains and charities competed to run new schools. But figures show that proposed faith schools have struggled to win competitions since they were introduced and have used an exemption in the law to win support directly from the Department for Education.
Between May 2007 and February this year, 16 of the 24 new faith schools that opened in the state sector did so without competition. No application to the DfE from a faith organisation to open a school without a competition was turned down, according to the figures. In comparison, just six out of 39 new schools without a religious character were granted the same exemption, the BHA said.
When religious groups did apply to competitions, they were more likely than other bids to be rejected, according to the figures. Only 35 per cent (eight out of 23) of faith school bids were successful in competitions, compared with 47 per cent (37 out of 78) of non-faith schools.
"If further proof were needed that the system is tilted in favour of state-funded religious schools, which discriminate in their admissions, and against inclusive schools, this is it," said BHA chief executive Andrew Copson. "When asked, the public does not want religious schools; people want more inclusive schools. But religious organisations continue to open schools by the back door, collaborating with local authorities to avoid competition entirely."
The figures - collated through a series of Freedom of Information requests - include private faith schools that switched to the state sector. They also include two proposed Catholic schools that have been approved to open in the London borough of Richmond, despite strong local opposition.
The law, which was amended in February this year, still calls for competitions to be held for new schools, although preference is now supposed to be given to academies and free schools.
But Richmond council is supporting the new voluntary- aided Catholic schools, due to open September 2013, without a competition. The BHA is seeking a judicial review of the decision.
Mr Copson said that avoiding competitions had been "phenomenally successful" for faith groups, with the proportion of schools with a religious character rising "alarmingly fast".
Maeve McCormack, policy manager for the Catholic Education Service, said that local dioceses would only consider opening new schools where there was considerable demand from parents, making a competition unnecessary.
"Opening a new school is a big undertaking, where we contribute significant sums of money," she said. "A lot of discussion would take place in advance of a bid, so at that point we want to get on with it and get the school opened. We know there is a real shortage of places at Catholic schools in London. We want to get moving as soon as possible, rather than waste time with a competition."
A DfE spokeswoman said that exemptions from competitions were not limited to faith schools.