The National Association of Schoolmasters and Union of Women Teachers (NASUWT) also called for teachers to remain anonymous while under investigation and for those who were exonerated to be removed from police files.

In the face of a growing tide of false accusations by pupils, a conference motion demanding an “obligation” on police to “consider a criminal sanction” against all false accusers was carried by the majority of the 800 delegates meeting in Brighton. They had been told that more than 12 allegations of criminal activity were made against members every month. Over the year 4 per cent result ed in convictions.

Delegates spoke of nervous breakdowns, sleepless nights and even suicide as they lined up to describe how the lives of colleagues and their families had been ruined by allegations, even when proved to be false.

The NASUWT is in talks with the Government about how to deal with false accusations, but John Thirsk, a teacher from Denbighshire, said more needed to be done. “The tide of malicious allegations shows no sign of waning. On a regular basis, teachers are still subject to the kneejerk reactions of many head teachers and local authorities who consider suspension the appropriate response to any allegations.”

Bryan Cook, from Wolverhampton, said that his office had seen false accusations increase sixfold after an episode of Coronation Street in 2003 in which Ken Barlow hit a pupil after being harassed and humiliated by him at school.

“Not one ended in a prosecution or got beyond an interview with police, but I can only imagine the stress,” he said.

Sarah-Jane Millington, from Accrington, Lancashire, told of a child claiming that his teacher had dropped him down a manhole during lunch-hour. Although the union had proved that he was shopping at the time, the member had been subjected to two disciplinary hearings before being cleared.

Jules Donaldson, a teacher from Sandwell, West Midlands, said: “Perhaps teachers, too, need to be litigious at times.”

Tim Collins, the Shadow Education Secretary, returned to the theme of violence against teachers when he spoke to the conference. Delegates had discussed the topic earlier in the week, demanding that violent pupils be thrown out of school.

Mr Collins promised to introduce a teacher protection Act. He told delegates that they had a right to feel safe in schools and repeated a pledge to scrap independent appeals panels, giving heads the final say over whether to allow disruptive pupils back to school. “Nobody should second-guess difficult decisions taken by heads and their staff, and no teacher anywhere should be forced to work with a violent child,” he said. He added that a Tory government would invest an extra £200 million a year to provide separate schools for the worst behaved, rather than force schools to take their share of difficult children.

However, he stepped back from an earlier commitment to reclassify assaults on teachers as “aggravated offences”, similar to attacks on police officers, and agreed only that the move would be considered.

Chris Keates, the general secretary, said she was very disappointed at “a crude attempt to grab the headlines”. “Although I admire Tim Collins for being honest about it and saying the press release had gone too far, I really don’t think that shows a party that’s in control of its policy,” she said.

Phil Willis, the Liberal Democrat education spokesman, backed calls for the prosecution of children, saying: “If an incident of harassment, verbal or physical abuse warrants prosecution in any other public place, it should warrant prosecution if it occurs in a school.”

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