Image copyright PA Image caption The proposed changes were announced in the wake of the Trojan Horse inquiries

Anti-extremism measures for schools in the wake of the Trojan Horse inquiries are rushed and could have unintended consequences, head teachers warn.

They claim proposed regulations could inhibit "free discussion" and are calling for a longer time for consultation.

The rules apply to England's academies, independent and free schools.

A Department for Education spokeswoman said they promoted "tolerance and respect of all faiths and cultures".

But a Christian campaign group says the proposals are a "classic case of the government over-reacting" and are so broad-ranging that schools could become subject to "every whim of the PC brigade".

'Over-regulation'

Following reports that schools in Birmingham were under pressure from groups promoting a hardline Muslim ethos, the Department for Education published amended proposals for new standards covering independent schools and academies.

These updated regulations, intended to reduce the threat of extremism and intolerance, include calls for schools to promote "British values", such as "mutual respect and tolerance".

But the Christian Institute, which is threatening legal action, says that the regulations are so "badly written" it could leave schools open to challenges over how these "values" are interpreted.

We make no apology for demanding high standards and the promotion of tolerance and respect of all faiths and cultures Department for Education spokeswoman

"They mistakenly advance the principle that political correctness equal British values. Accordingly they could be used to punish any school in the independent sector which has a religious ethos, a set of traditional beliefs, or who don't over-promote every minority group's world view," says the institute's chief executive, Colin Hart.

The institute claims that it could mean that Christian festivals such as Christmas could be "downgraded" so as "not to offend atheists and those of other faiths".

The Department for Education says that it is "simply untrue" that there could be any such consequence from its proposed regulations.

But head teachers have also raised concerns about the proposed requirements.

Malcolm Trobe, deputy general secretary of the Association of School and College Leaders, says there is a danger of "over-regulation".

In the wake of such "high profile" cases as the Trojan Horse investigations, he says there is an "inherent risk" of a "knee-jerk response".

"This is a very sensitive and difficult area," says Mr Trobe. But he warned that the proposals could make teachers reluctant to discuss controversial topics - and as a result, rather than protecting free speech, the proposals could inadvertently limit free speech.

"It will no doubt be argued that there is no intention of stifling such discussion, but there should be no power to do so; a secretary of state cannot bind her successors, and once a power is available it is likely to be used, not always for the original purpose," says ASCL's official response to the education department.

The Independent Schools Council, representing independent schools, has highlighted concerns about a lack of time for an adequate response to the proposals. The consultation was launched in June and will end next week.

A spokeswoman for the Department for Education rejected the concerns.

"The Independent School Standards are designed to ensure every school prepares children for life in modern Britain. We make no apology for demanding high standards and the promotion of tolerance and respect of all faiths and cultures.

"It is simply untrue to say that the proposed changes - which received 1400 responses and last six weeks - would prevent teachers using gender-specific terms or require schools to downgrade Christian festivals.

"We have received a letter from the Christian Institute's legal representatives and are considering our response."