A whistle-blower at a north Norfolk high school has helped expose the growing army of unqualified staff taking classes across the county.As many as 180 cover supervisors are employed in Norfolk's 52 high schools, looking after classes when teachers are absent or busy.

A whistle-blower at a north Norfolk high school has helped expose the growing army of unqualified staff taking classes across the county.

As many as 180 cover supervisors are employed in Norfolk's 52 high schools, looking after classes when teachers are absent or busy.

The supervisors, who earn much less than qualified teachers at �14,000-19,000 per year, are only supposed to hand out lesson plans prepared in advance by teachers, and to maintain order during the lessons.

But a former headteacher, who went undercover last term to be employed as a cover supervisor at Sheringham High, said it was 'impossible' for them to avoid taking on the role of teacher at times.

Tony Callaghan said he took the job at Sheringham because he was concerned about classroom standards.

He said: 'I wonder how many parents realise that when their youngsters come home from secondary school and say they had a 'new teacher today', that new teacher may not be a teacher at all.'

Mr Callaghan said that during his time at Sheringham High he 'struggled'. He said: 'As a qualified teacher I thought I would be able to deal with the various tasks expected of me. But I had been out of the classroom for 10 years and I found it extremely difficult to simply supervise classes of teenagers across the whole range of the curriculum.

'How could I answer the questions or deal with the problems raised by the students if I had little or no knowledge of the subject matter?'

He said many schools were employing cover supervisors rather than qualified teachers to save money, and that supervisors should be given credit for their 'versatility and tenacity in the circus that education has become.'

Sheringham High head Tim Roderick said: 'Our school has a fantastic set of cover supervisors who provide a range of skills and support to students, when teaching staff are unavailable.

'These staff are fully trained and supported. They manage classroom activities and behaviour and give students pre-set work to carry out, under supervision.'