The Professional Association of Teachers (PAT) said allegations levelled at its members rose to 30 last year from 19 in 2001 - but this year there had been 36 by late May alone.

It said the "overwhelming majority" proved to be untrue.

The union - the smallest of the teachers' organisations - demanded at its annual conference that teachers should have the right to anonymity unless they were convicted of a criminal offence.

The government has so far ruled this out.

But in response to repeated complaints from teacher unions it has set up "co-ordinators" across England to speed up the investigation process.

'Must be investigated'

PAT delegates, meeting in Harrogate, said childcare workers including teachers often suffered the trauma of their names being published when false allegations were made against them.

Former union chairman May Castrey said any such allegation had to be taken seriously and investigated in accordance with agreed procedures.

"We also know that such allegations are sometimes false, even malicious.

"We know that one of the risks we face daily is that of having false accusations made against us and finding ourselves suddenly suspended while investigations are carried out.

"But experience shows that knowing all this does not lessen the shock and distress when it occurs."

Months of worry

She told delegates about a teacher accused of assaulting a child who was not given any details of the alleged offence.

After 10 weeks, and the intervention of the union, the police and social services said "no further action is considered necessary".

But the teacher was left worrying whether that meant they had decided something had happened but it was not serious enough to warrant further action.

Ms Castrey said it was another 17 weeks before the investigators confirmed there was no case to answer.

As well as anonymity, teachers in such a situation should be able to expect "respect, courtesy and consideration" and to be told what the allegations were.

They should be able to put their case to the investigators and to be told "speedily and in an understanding way" their and the reasons for it.