The people tasked with assessing the role others perform in teaching jobs lack the necessary skills to be fair and reliable.

This is the damning assessment of Ofsted outlined in a new report by think tank Policy Exchange, which explained that many schools inspectors are employed on a part-time basis by private firms and do not have much understanding of what it takes to teach - especially in primary schools or special needs classes.

Policy Exchange wants inspectors to be subject to an accreditation exam before they are allowed to assess schools and teachers.

Entitled Watching the Watchmen, the report also suggests Ofsted should stop the use of inspectors from private firms.

Report author Jonathan Simons said: "We need an independent schools regulator that inspects all schools freely and fairly. But it is also why we must make sure that the school inspection regime is fit for purpose."

He added: "More needs to be done to drive up the quality of inspectors. Heads and teachers must feel confident that the person running their eye over their school is a specialist, preferably with recent teaching experience."

Teachers should be left to do their jobs and it should be the inspectors who evolve and adapt to accommodate them rather than vice versa, explained the report. 

Ofsted does currently require its inspectors to have five years' teaching experience, as well as relevant and recent experience of the area they are inspecting and Michael Cladingbowl, the regulator's national director for schools, said the watchdog would welcome suggestions of how inspections could develop in upcoming years.

However, he stressed that Ofsted had played a major role in improving the standard of schools in England over the past two decades.

Does the think tank have a valid point? Despite Ofsted's selection process, are inspectors lacking an adequate idea of what it takes to teach at certain schools?

Let us know what you think about the report.