The National Association of Head Teachers (NAHT) has said that only those who hold qualified teacher status (QTS) should be allowed to carry out Ofsted inspections.
Russell Hobby, general secretary of the NAHT, responding to revelations that personnel without QTS are working on behalf of Ofsted - the Office for Standards in Education, Children's Services and Skills - said that only those who are qualified for jobs in education should be allowed to rate teachers.
"I don't know how anyone who isn't qualified could provide a meaningful assessment of the quality of teaching," he said.
"Schools' reputations and teachers' careers are made and broken on the basis of these reports. Parents think they are authoritative."
Schools which are only judged 'satisfactory' or 'inadequate' can face monitoring procedures and be served with notices to improve.
A leaked email seen by the Times Educational Supplement, sent by one of the firms which provide inspectors for Ofsted, revealed that the company had not seen QTS as an issue before. The same company is said to employ at least five lead inspectors without QTS accreditation.
When asked for his view on the issue, Brian Lightman, general secretary of the Association of School and College Leaders, echoed the words of Mr Hobby.
"It is essential for the credibility of the inspection service that anyone who is inspecting a school has the appropriate qualifications and experience in that sector," he said.
"It is extremely worrying that a contractor is not aware of its inspectors' backgrounds."
However, an Ofsted spokeswoman told the Press Association that all its inspectors were trained to do their job.
"Lay inspectors ceased to exist in 2005. However, a very small number became additional inspectors. Like all inspectors, they have many years of experience in education and inspection and are extremely knowledgeable about schools. All inspectors receive ongoing rigorous training," she said.
Posted by Alan Douglas