Philip Hunter, president of the Society of Education Officers and director of education for Staffordshire, says analysis of GCSE results for schools after inspection shows the process has not helped them to improve.
Putting a hotly-contested figure of pound;1 billion on the cost of the first four-year round of inspections by the Office for Standards in Education, Dr Hunter said: "It is a lot to pay for public confidence alone."
He matched GCSE results for 300 secondary schools inspected by OFSTED in six shire counties and one metropolitan authority to the average improvement for each authority. The study covered Devon, Essex, Hampshire, Kent, Oxfordshire, Staffordshire and Birmingham.
Dr Hunter said only 44 per cent had seen results improve by more than the authority average in their first year post-OFSTED. Results at the rest improved by less than average, or even deteriorated. In the second and third years after inspection, the margin closed, but even after three years, inspected schools with below-average improvements still formed a majority.
"It's worth spending that much per year if the process also improves schools in some way. But it is clear that is not happening. It's a value-for-money question," Dr Hunter said. His criticisms form part of a wider attack on the previous government's reforms and a warning for Labour which he makes today in The TES (page 24), and in his opening speech at the SEO conference in Bradford.
He says Tory attempts to create a market in education through the national curriculum, grant-maintained schools and OFSTED have done little to raise standards, but have cost pound;3bn - at a time when local government spending has been under attack.
Labour must have a clear vision of what it wants to achieve, backed by evidence-based policies, to avoid the same mistakes, he says.
But OFSTED spokesman Jonathon Lawson said Dr Hunter had failed to grasp the aim of inspection - to highlight problems and provide data which schools can use as a basis for improvement.
"The purpose of inspection is to tell schools and the people responsible for them and parents what is going on in those schools," he said.
Dr Hunter argues that OFSTED spends pound;140 million on inspections annually, a figure matched by schools and LEAs. OFSTED says its inspection budget for the whole four-year cycle was only pound;300,000.
Opinion, page 24