The rapidly growing government bill for new buildings at faith schools has come under fire from campaigners.
Voluntary-aided religious schools are usually supposed to pay 10 per cent of their capital costs, but figures show that the amount they are contributing has dropped significantly over the past five years.
In 200809, voluntary-aided faith schools paid just 7.5 per cent of the bill, leaving an extra pound;18.4 million to be picked up by the taxpayer. In 200405, schools paid more than 9 per cent of the bill, creating a shortfall of just pound;5.4 million.
The growing burden on the public purse comes as spending on improving all schools' buildings has increased significantly with the Building Schools for the Future (BSF) programme, which aims to refurbish or rebuild every secondary in England.
Ministers agreed to scrap the 10 per cent contribution from voluntary- aided schools taking part in BSF. The scheme has so far spent pound;150 million upgrading 25 voluntary-aided faith schools.
There was no similar deal to exempt such schools from paying towards improvements made at primary schools.
The land and buildings at voluntary-aided schools are normally owned by a charitable foundation.
The school is its own admissions authority and the governing body, rather than the local authority, employs the teachers. This means that pupil places and certain teaching posts can be reserved for followers of the faith.
The Accord Coalition, which campaigns for inclusive education, criticised the growing state subsidies for new buildings at religious schools.
Rabbi Dr Jonathan Romain, the group's chairman, said: "Perhaps the Government has recognised the financial reality that religious groups can't afford to pay as much as they once did, but not the social reality that religious discrimination is unacceptable in the 21st century.
"Taxpayer-funded public services should be for the public, not one segment of it.
"It is vital for the long-term health of society that children of different traditions grow up together and learn to interact on a daily basis."
But Rob Gwynne, head of school development for the Church of England, said parents value the strong ethos that faith groups bring to education, not their economic contribution.
"The huge government investment in capital building projects over the past five years has meant that some faith groups, the Church of England included, have had to find large amounts of extra money to meet our target of providing 10 per cent of capital costs," he said.
"In fact, the actual amount given has risen significantly from around pound;50 million to pound;56 million a year, although even this has not been enough to consistently meet our target for every single building project.
"In these cases, the Government or local authority has tended to plug the gap with some funding to ensure that the building work goes ahead."