The government is said to be considering making it easier for the Church of England to take control of state schools

Secular campaigners have criticised reports that ministers are considering making it easier for the Church of England to take control of state-funded schools.

The British Humanist Association (BHA) has written to the education secretary, Michael Gove, describing the plans as "the single most threatening development in the area of faith schools since their expansion began in 2001".

The criticism follows a report that the government is preparing to smooth the path for community schools that wish to opt out of local authority control and become academies backed by the Anglican church. At present, there have to be separate consultations dealing with academy and faith status, but the government is looking at combining these in a single step, according to the Times Educational Supplement.

According to tThe TES reported that the church was also looking at fostering looser partnerships with schools that would not take on a faith designation.

The BHA's chief executive, Andrew Copson, said: "If the church and the government have their way and their ambitions are realised, the church will become the single largest provider of schools, totally funded by the state. That risks a majority of schools being allowed to discriminate religiously in employment, discriminate religiously in admissions, and teach curricula skewed towards Christianity across the board.

"This is a potentially massive takeover. It is unsurprising that a 'national' church to which 80% of the population do not actually see themselves as belonging and whose services are attended on a monthly basis by under 5% of the population should see its only hope for future survival as a state-funded service provider. But the idea that government, which should be providing schools inclusive of all, is facilitating this drive with public money is shameful."

The BHA fears that the church will prove to be an attractive backer for schools that have left the local authority fold but are still looking for the support of a larger organisation.

The campaign group urged ministers not to relax the existing rules for any maintained school without a religious character looking to convert to a religious school.

A spokesman for the Church of England said: "As local authorities continue to decline in influence and capacity, there is an evident interest from non-church schools in becoming part of the church school family and diocesan boards of education are responding to this process, not driving it. Dioceses already provide a significant infrastructure with which community schools might have something in common, thus becoming an obvious place for them to look for a 'safe haven'."

Campaigners for secularism have also drawn attention to plans by a Catholic group linked to the conservative organisation Opus Dei to open two new secondary schools. The schools will be fee-paying and are due to open by September 2013.

The Pact educational trust, which already runs two prep schools in south London, says the new schools will be non-selective on academic grounds, and as "affordable as possible".

In a statement, the trust said: "In Pact schools, which are inspired by the teachings of the founder of Opus Dei, St Josemaría Escrivá, parents are seen as the primary educators and are strongly involved in the schools."

It emerged last year that every state school in England is to receive a new copy of the King James Bible from the government – with a brief foreword by Gove, to mark the 400th anniversary of its translation. Every primary and secondary school will be sent a new copy of the 1611 translation by Easter.

The Department for Education estimates the cost of the Bible scheme at £375,000, and is seeking philanthropic sponsorship.