Squads of trained, neutral governors should be set up to deal with the rise in cases where heads are accused of bullying staff, union officials have demanded.
The idea has already been tried out in one area. Now, the NUT national executive member involved is calling for the move to be formalised and introduced nationally.
Pete Bevis said he had seen a significant increase during the past decade in cases of teachers being bullied by their heads.
The Barnsley NUT secretary said his members were not confident their complaints got a fair hearing because cases were usually heard by governors at the same school.
"It is not a level playing field," he said. "You are up against a group of people who want to be fair, but may find it difficult to be fair. (Governors) can find it very difficult to accept that they have appointed somebody who is a bully.
"If a head looks them in the eye, they will feel duty bound in the overwhelming number of cases to be supportive of the head because they know the consequences of finding against the head is that they would find their position as governors untenable."
Some cases in Barnsley had been heard by panels of governors from other schools. Mr Bevis believes the policy could work everywhere. A bank of trained governors could be put on standby and paid to hear grievances against heads, he said.
"You could give confidence to the individual that they will be listened to by a group of people not beholden to the school," he said.
Phil Revell, chief executive of the National Governors' Association, said: "We are supportive of governing bodies supporting each other. In any case, where they feel too close to the issue - and that is quite likely where there is a situation between a head and a member of staff - it is very difficult to come to such a review with a genuine independence of mind."
This week, an NUT survey on teachers' mental health (see page 19, opposite) found that two-fifths of staff had been victims of bullying or harassment at work and that more than one-fifth were often in conflict with their managers.
Mr Bevis said much of the problem originated with ministers. "It is because of government downward pressure," he said. "They pressurise the local authorities, who put huge pressure on headteachers, and they in turn are putting huge pressure on other colleagues in school.
"It is kicking-the-cat syndrome - you are at the bottom of the pile and you are getting a good kicking. It's taking its toll on teachers.
"But it is by no means all heads. Certain headteachers tell me they are bullied themselves."