Faith schools in Britain are to be investigated by the European Commission after complaints that they discriminate too widely on religious grounds when recruiting staff.
Church of England, Catholic and Muslim schools will be scrutinised to see if expressing a preference for religious teachers - and having the right to pay them more than non-believing colleagues - breaches equality laws.
European Union rules state that a school must be able to prove a "genuine occupational requirement" in order to discriminate in favour of a religious candidate. However, the British Humanist Association, whose complaints sparked the inquiry, says that describing religious adherence as "desirable" falls short of this standard.
"If religious practice is a `desirable' quality and not an essential one, then it cannot be a genuine occupational requirement," Richy Thompson, campaigns officer at the BHA, told TES. "It should either be essential or not there at all."
The case also brings into question government guidance that gives voluntary-aided faith schools, which are part-funded by religious organisations, the freedom to apply "religious criteria when recruiting or dismissing any member of their teaching staff".
The schools can give preference to religious candidates in "recruitment, remuneration and promotion", the Equality Act guidance adds. It says that academies, free schools and independent schools with a religious character "generally operate under conditions which mirror those in voluntaryaided schools".
The rules for voluntary-controlled faith schools, which are state-funded, are tighter: they say faith can be taken into account only when appointing the headteacher and "reserved teachers", who are chosen for their ability to deliver religious education. Reserved teachers cannot make up more than a fifth of teaching staff.
The BHA has asked the commission to investigate whether the government guidance is at odds with the EU directive.
Paul Barber, director of the Catholic Education Service, told TES that faith schools should determine "on an individual basis" whether they required a religious candidate for a particular role.
"They need to look at the full circumstances of each job," he said. "A particular vacancy may well qualify to be a `genuine occupational requirement' at one time, but it may not do at a different school or at a different time." He said he believed the Equality Act was in line with EU rules.
A spokesman for the London Diocesan Board for Schools, which runs 133 primary schools and 20 secondaries, said that its schools usually sought a "Christian commitment" only when filling senior leadership positions.
"However, even then, in the majority of those cases, a school will be looking more for someone who will actively support the Christian traditions and ethos of the school, rather than a `card-carrying' member of the Christian church," he added.
"We have senior staff in our schools who are adherents of various faiths and many who have no personal faith. What they have in common is that they are committed to supporting the values of our schools and working with the community, the local clergy and the diocese for the good of the children."
Talha Ahmad, chair of the education taskforce at the Muslim Council of Britain, said Muslim schools tended not to state a preference for Muslim teachers but received very few applications from non-Muslim candidates.
"At voluntary-aided schools, there's no obvious discrimination towards any specific faith, although if staff are recruited primarily to teach Islamic studies you might have a Muslim teacher," he said. "But, in my experience, you don't come across applications from non-Muslims."
At Muslim independent schools, he said, "shoestring budgets" caused by low fee levels meant that teachers were often headhunted. "They will typically recruit people from within their network," he said. "They rely on the goodwill of individuals who will work for less pay. So although I don't think there's any deliberate discrimination towards Muslims, those are the people they tend to come into contact with."
The European Commission placed a similar investigation on hold last year after ruling that no evidence had been provided of "incorrect application of the laws at stake". However, the commission has agreed to reconsider the case after the BHA's submission of job adverts as evidence.
Papers obtained by the BHA through the European equivalent of a Freedom of Information request show that the government told the commission it believed a school could "give preference [to religious candidates] in respect of appointment to any teaching position" if that school could prove it had a "genuine and substantial religious ethos".
The government said this could be justified in some cases because of "the pastoral responsibilities of all teachers, regardless of subject or seniority".
A spokesman for the commission confirmed that it was considering the complaint and had made contact with the British authorities.
A spokesman for the Department for Education said the government's guidance allowing faith schools to apply religious criteria was in line with the "genuine occupational requirement" rule set out in the EU directive.