A Durham University study of secondary schools named by government inspectors as failing shows that all but two were in the poorest parts of the country. None were in the most prosperous areas.
Yet, a week ago an Audit Commission investigation found that some schools in affluent areas were getting GCSE results no better than those in deprived ones.
Ofsted last night accepted that it had not, until recently, had the mechanism to identify easily poorly performing schools in prosperous areas, but said that was now in place. A spokesman said he expected that inspectors would soon be failing poor middle-class secondary schools.
The Durham study, for tomorrow night's Dispatches programme on Channel 4, analysed the proportion of pupils on free school meals - an accepted measure of deprivation - for 83 failing schools.
At 59 schools, more than 35 per cent of pupils were eligible for free meals; the national average is 18 per cent. At 21 of the schools the percentage taking free meals was between 22 and 35 per cent and at three the percentage was between 14 and 21 per cent.
Mark Wightman, of Durham University's Curriculum, Evaluation and Management Centre, who analysed the figures, said: "I agree with the Government that poverty should not be an excuse for failure but there doesn't appear to be anything to take into account the difficulties teachers have with their intake.
"Some of the failed schools are actually doing slightly better than you might expect, given the range of ability of their pupils. Ofsted seems to be punishing schools for a whole range of social evils that they can't do much about."
Equally, he added, there were some schools which looked good in terms of the proportion of pupils achieving A to C grades where a lot of those Bs and Cs should be As and A*s.
Mr Wightman did not analyse primary schools and accepts that some primaries in middle-class areas have been failed.
A spokesman for Ofsted said it did not disagree with the analysis but pointed out that some schools with a high proportion of pupils taking free meals had overcome the handicap.
"We have no doubt that we have got it right with these failing schools. In identifying these schools, we are bringing them attention, support and extra resources and educational hope to the children in them."
Ofsted was concerned, he said, that some schools in prosperous areas were under-performing. "Until recently we have not had the statistics or mechanism easily to identify schools which are doing well by national averages but underachieving. We now do. We will be focusing more on coasting secondary schools."
In the programme, Professor Tim Brighouse, Birmingham's chief education officer, calls for an independent inquiry into Ofsted. He recently had a series of disagreements with Chris Woodhead, the Chief Inspector of Schools, over a report on the authority.Reuse content