Addressing the North of England conference this week, Professor Davie, formerly director of the National Children's Bureau, went on to say that the concept of special needs itself may have to be scrapped if all pupils are to have their needs addressed, and not just the most vulnerable fifth currently thought to require additional help.
"The question must arise," he said, "as to the appropriateness of drawing a line at a notional 20 per cent of the school population and placing them in a categorical group which may become stigmatising and to that extent self-defeating."
The 20 per cent category ignores exceptionally able children, pupils for whom English is a second language, children who have been severely ill and those with domestic problems - all of whom may need help.
"These examples already begin significantly to stretch the definition of special needs and take us into or near the position where we are considering a majority of pupils," he told the conference.
Schools, he said, should resist the view that some children need "some kind of special approach whereas the rest can be treated more or less the same".
New figures from the Department for Education and Employment show that 2.7 per cent of children nationally have "statements" - the formal description of their needs which usually includes promises of extra help.
When the system was introduced in 1981 the intention had been to give statements to only 2 per cent of the child population. The steady rise in the numbers is seen by many, including Professor Davie, as evidence of how hard it is to set a boundary beyond which extra help is not available.
Professor Davie called for schools to consult individual children on a more systematic basis before taking decisions about their future. "A proper regard and respect for the views of others, whether child or adult, are central to the educational process," he said.
"There is some evidence that consulting and involving pupils, once introduced, is so self-evidently valuable and relevant that teachers and schools are unlikely to drop this approach."
* Labour's commitment to the increased use of technology in schools was due to be spelled out yesterday by David Blunkett, the party's education spokesman, at the conference.
Mr Blunkett was expected to single out schools in Cumbria as one example of the effective use of computers. One primary, Orgill in Egremont, has 150 computers for its 210 pupils and pupils can take the equipment home.