A former top education mandarin has suggested that the Prime Minister's latest reforms to education ignore 50 years of evidence from schools.
Sir Michael Bichard, who was permanent secretary at the Department for Education and Employment between 1995 and 2001, also said the education Bill published this week could lead more pupils to drop out of school.
The accusations came as the TES learned that the Bill, which aims to change the structure of schooling by creating more state-funded independent schools, will re-open the debate over the 11-plus.
Labour backbenchers say they will try to amend the Bill to abolish selection in England's 164 remaining grammar schools.
Sir Michael, who led the inquiry into the vetting of school staff following the Soham murders, last night recalled how he and David Blunkett, then education secretary, agreed in 1997 that school improvements should be about standards rather than structures.
"Less than a decade later we are once again mired in a debate which is essentially about structure," he said delivering the TES-sponsored annual City of York education lecture.
"That may be because the Prime Minister now believes that the only way to improve standards for all is to change the structure.
"If so that flies in the face of the evidence of the past 50 years - not least that even since 1997 improved performance at school level does not lift the performance of the weakest pupils in those schools.
"The problem with developing what the white paper calls a 'radical new school system' is that, as with any structural change, it consumes energy, causes uncertainty and can distract from the substance whilst giving the impression, at least, that much is changing."
Sir Michael said that a more market-orientated secondary system would lead to less tolerance of disruptive behaviour and force more pupils to drop out.
"A perverse consequence of the current reform process could be that more young people end up dropping out because their needs cannot be accommodated in an educational mainstream so attuned to raising the standards for the majority that it is unable to give adequate attention to those who struggle," he said.
Sir Michael, now rector of London's university of the arts, stressed before the speech that his comments were not meant as a direct attack on the Bill but aimed to add to the debate about low-achieving students. There were many positive aspects of the legislation, he said, particularly the drive to use pupil data better.
"Underachievement in schools may have more to do with teachers not having developed strong skills in data analysis and assessment than it does with the structure of the school system," he said.
Meanwhile ministers' desire to stress that their reforms will not lead to any new selection has backfired.
David Chaytor, the Labour MP for Bury North and a member of the Commons education select committee, said: "The anomaly of the Government now being so profoundly anti-selection for most parts of the country, but allowing it to continue elsewhere is totally incoherent." He said it was certain that an amendment abolishing the 11-plus would be tabled and predicted huge support among backbenchers.
Ian Gibson, Labour MP for Norwich North, said: "I would put my last penny on it." Mr Blair has said that a "war" over the remaining grammars would dominate the education debate.
Education bill, news 16-17