The department for education and skills has issued guidance for schools and head teachers in the light of the terrorist attacks warning them they must only give 'accurate information' and provide an 'appropriate' way to discuss the issues.
One head teacher has already told a school assembly that he is against the war and is prepared to defy his governing body.
Peter Stephenson, 45, head of Exeter Road Comprehsensive School, Exmouth, Devon, said: 'I understand that not everybody will share my view, but I think it is important to be honest and express my opinions'.
He said: 'After years of hiding in the closet, I'm going to say what I think. I'm going to wear my CND badge every day and I'm not going to take it off for governors' meetings'.
Cllr May Hardy, a member of governors at Mr Stephenson's school, condemned his actions. She said: 'I do not believe you should ever take politics into the classroom'.
John Hart, Conservative executive member of Devon CC in charge of education, said: 'I do not think any teacher should air his personal views in front of their children'.
The DfES has now issued guidance to schools and teachers that says: 'Schools can help to provide accurate information, challenge crude sterotyping and provide a safe environment in which children and young people can explore their understanding and come to terms with their fears.
'Schools should maintain an atmosphere as normal as possible, neither denying recent events nor letting them take over'.