Norwich, which has the highest proportion of atheists in England, according to the last census, is to gain an academy with a Christian ethos, while a further three are planned for West Sussex, which has low levels of church attendance.

The National Secular Society said the academies undermined government claims to promote parental choice, as they would leave many families with no choice but to send their children to a faith school. Keith Porteous Wood, director of the society, said non-religious teachers in those areas would also feel uncomfortable. “Only a minority will be church-goers,” he said. “As a consequence, they may feel vulnerable over promotion, if not their jobs.”

The 2001 census indicated that Norwich was the least religious city in England, with 37 per cent of its population saying they had no religion or declining to say they were believers.

However, the council has approved the opening of an academy backed jointly by the Anglican diocese of Norwich and Graham Dacre, a devout Christian and millionaire founder of the Lind Automotive Group. The school will replace Heartsease High School, which has no religious connections.

In West Sussex, three other schools with no religious affiliation - Littlehampton Community School, Boundstone Community College and King’s Manor Community College - are expected to close to make way for academies backed by Woodard Schools, an organisation that runs independent and state schools with a strong Christian ethos.

Figures show that church attendances in the districts surrounding the three schools are well below the national average, particularly among teenagers - 3.9 per cent of its 15- to 19-year-olds attend church compared with a national figure of 5.3 per cent.

David Bilton, chair of Woodard Schools, said the academies were at the feasibility stage and that there would be consultation on their “faith provision”. “We educate 27,000 pupils and although many of them are Anglicans, a growing number are from different faiths or of no faith at all,” he said.

Christian organisations have become heavily involved in the academies movement, sponsoring 24 of the 84 that have opened. The Church of England is committed to sponsoring 100 faith designation academies, and is working on plans for the first multi-faith Christian and Muslim academy in Oldham, Greater Manchester.

Pat Langham, president of the Girls’ Schools Association, who will address the organisation’s annual conference in Leeds next week, said academies are not the answer to forging independent and state school links.

She called for increased funding for the IndependentState School Partnership initiative, which receives pound;2.2 million a year.