The General Teaching Council of England has been accused of watering down its new code of conduct after religious groups complained that teachers would have to promote homosexuality.
Faith groups raised fears that a duty to "promote equality and diversity" would force teachers to contradict their own beliefs. They were also concerned at the suggestion that teachers "challenge discrimination, stereotyping and bullying, no matter who is the victim or perpetrator".
But the code of conduct, which was published last week, has toned down such changes. Following consultation, the code now says teachers should only "demonstrate respect for diversity and promote equality" and need only challenge discrimination when it is unlawful.
Terry Sanderson, president of the National Secular Society, accused the GTC of betraying "vulnerable pupils to satisfy religious demands". "This is a truly disgraceful capitulation on the part of the GTC," he said. "Gay children and even those perceived to be gay because they might be effeminate or tomboyish now have a level of protection removed from them."
Mr Sanderson said that while most teachers would recognise vulnerable children being victimised, "bigoted evangelical teachers" were being given "carte blanche to add their own disapproval to the bullying".
Gay rights charities have also criticised the move for failing to tackle homophobic bullying in schools sufficiently.
The new code, which starts in October, sets out standards of conduct for 540,000 registered teachers in England. It will also be used in disciplinary proceedings.
Initial opposition was raised during consultation by groups including the Catholic Education Service and the Church of England, which between them operate more than 6,000 state schools.
The Church of England had said that the new code risked creating a "conflict between teachers' professional responsibilities and their personal faith or philosophical commitments".
Oona Stannard, chief executive of the Catholic Education Service, said the original call to challenge discrimination could have been used to oppose all faith schools.
This week, Ms Stannard said she was satisfied that the service's concerns had been taken on board.
"I was always confident that the intention was not to compromise any teachers or put them in a position where they would be teaching against their beliefs," she said. "But when many teachers told me thatwas what they feared, it was necessary to make sure that there was no ambiguity. I am confident that the changes will mean that teachers will not be required to teach against their beliefs."
The Christian Institute, an evangelical charity, said the original proposals could have led to legal challenges. Mike Judge, a spokesman, said: "If a child asks a question about a teacher's faith, a Christian teacher shouldn't be disciplined for giving an open and honest answer. Nor should they be forced to promote ideas or behaviour with which they disagree."
The GTC said the code had been amended to take into account a wide variety of responses. It said it was "consistent with our commitment to, and strong record on, equalities and will serve all children well".
Another concern was that the code might be used to interfere in teachers' private lives. A spokeswoman said the code made it clear that teachers have a right to a private life, but are expected to maintain "reasonable standards of behaviour".
DAWKINS DVD TO BE SENT TO ALL SCHOOLS
Every school in England and Wales is to receive a free DVD of Growing Up in the Universe, Professor Richard Dawkins' 1991 Royal Institution Christmas Lectures for Children.
The controversial film is being distributed by the British Humanist Association and funded by the Richard Dawkins Foundation for Reason and Science to celebrate the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of On the Origin of Species.
Professor Dawkins, vice-president of the association, said: "Increasing young people's understanding of science has never been more important."