The National Association of Head Teachers launched a campaign today at their annual conference in Bournemouth, renewing calls for a change in the law.
Malicious allegations from parents and subsequent press exposure can wreck careers and lives, while unnamed accusers walk away with no punishment, they said. Some teachers have even been driven to suicide.
Headteachers are pushing the Government to make it easier to take parents who make malicious allegations to court.
They want unfounded allegations automatically removed from Criminal Records Bureau files and clear local authority protocols for putting matter right.
The campaign calls upon councils to keep stricter records of parents who make repeated spurious allegations.
The NASUWT teachers' union has recorded over the past 15 years 2,210 teachers who have been accused of physically or sexually assaulting pupils, but only 88 have led to conviction. The NAHT believes some authorities are negotiating out-of-court settlements with parents to avoid going to court, and fears this could be acting as an incentive to accusers.
Its campaign, Guilty by Accusation, is being led by Dame Mary MacDonald, head of Riverside primary in North Shields, Tyneside.
Two parents stormed into the school in 2005 accusing her of hitting an infant school girl during an assembly, and refused to leave until the police came. Dame Mary collected dozens of witness statements to show she had not been near the child and a short police inquiry concluded the accusation was unfounded. But the rumours took a long time to dissipate.
It was this, and several other false accusations against herself and staff, that led her to contact local MPs to push for change.
"It is not about fudging any issues of child protection, as it is important that all allegations are fully investigated," she said. "But the current system is weighted in parents' favour.
"If a woman makes a false allegation of rape, she can be prosecuted, so why not a parent accusing a teacher? Headteachers in particular are vulnerable as parents sometimes want to get back at you for something. I've seen families destroyed by this. I was lucky and it was relatively easy to disprove what I was accused of, but other teachers have had it much worse."
Ray Tarleton, headteacher of South Dartmoor community college, was cleared last year of striking a boy he had been forced to restrain. He said that suspensions of headteachers should only be used as a last resort after allegations are made, because they could "paralyse" a school. "The amount of effort that went into investigating my case was staggering," he said.
Mick Brookes, general secretary of the NAHT, said that an inversion of justice had gone on too long. He said: "We have clear evidence that lives are being damaged and careers ruined by a failure of the law to adequately protect people who are innocent of accusations levelled against them". The NAHT campaign follows similar calls at the annual conferences of other unions this year. The NASUWT passed a motion calling for members to hold "refusal to teach" ballots against pupils who had made false claims but were still in the school. The National Union of Teachers called for withdrawn or unfounded allegations to be removed from teachers' CRB records. The Department for Education and Skills has responded to the NAHT campaign by highlighting guidance it issued last year which stressed that confidentiality should be maintained during investigations.
But the union says the guidelines do not go far enough.