Head teachers are protesting against what they claim is a significant increase in assaults on school staff by parents.

And they want the right to exclude the children of parents who have behaved aggressively while on school premises.

It's evidence of poor parenting - and a long-term social problem in which parents don't know how to behave properly and don't know how to bring up their youngsters

Chris Thatcher, primary head teacher

These violent incidents have been likened to road rage and dubbed "school rage" by head teachers attending the National Association of Head Teachers' conference in Harrogate.

Among the factors fuelling this increase in aggression, say head teachers, is a cycle of poor parenting, which means that neither parents or children know how to behave.

"It's evidence of poor parenting - and a long-term social problem in which parents don't know how to behave properly and don't know how to bring up their youngsters," said Chris Thatcher, a primary head teacher in Coventry.

And he rejected claims that it would be unfair to expel pupils because of the misbehaviour of their parents.

'Zero tolerance'

Mr Thatcher said when parents were threatening the safety staff it was no longer possible to work with the family and that a "fresh start" in another school would help the pupil.

The NAHT says last year there were 140 cases in which parents were banned from school premises after violent incidents.

The head teachers' union says this is the "tip of the iceberg" and that there has been a "significant deterioration" in the behaviour of parents collecting pupils from school or attending parents' evenings.

And in response the union says it wants a "zero tolerance" policy towards unruly parents, including the right to exclude the children of disruptive parents.

"If the relationship between the parents and the school has irretrievably broken down because of ... violence or threatened violence, there is absolutely no reason why the school should be expected to educate their child," says the union.

Threats

The union is also calling for a change to the law on parenting orders, so that parents convicted of offences against school staff could be banned from school premises.

And the union urges local education authorities to take a tougher line to protect teachers from aggressive parents - and for the courts to pursue incidents in which school staff are threatened.

The union's general secretary, David Hart, said the "rising tide" of assaults and threats of violence against his members must be reversed as soon as possible.

"It is absolutely intolerable that public servants should be subjected to increasing risk of injury and abuse," Mr Hart said.

"Of course we will continue to recover substantial compensation on behalf of our members.

"But it would be infinitely preferable if firm and decisive action were taken by government, local education authorities and law enforcement agencies to protect those responsible for running vital public services," he said.

A head's story

Head teacher Roger Brind, who has been physically assaulted twice and verbally abused on a number of occasions, said violence towards staff was 10 times more prevalent now than when he became a head in 1980.

While almost all the parents at his school - Trelai Primary in Cardiff - were very supportive a small minority caused problems, he said.

David Hart said the situation was "absolutely intolerable"

"We have had to introduce more security, so it's harder to get to staff, which I regret, because I like to run an open, welcoming establishment," Mr Brind said.

The increased risk of violence was having an effect on recruiting staff to senior posts, he said.

"I've had fewer and fewer people applying for senior positions," he said.

Commenting on the two occasions when he was assaulted - one time a parent spat in his face, another a parent held a knife to his face - Mr Brind said: "It's like being put through a mangle and wrung out".

"It is stressful - I've had time off work through stress after these incidents, and I'm a strong character, not the type of person to be pushed over easily," he added.