Charles Gains, a former lecturer in special educational needs, told delegates at the recent International Special Education Congress that many schools had been left unable to cope with the influx of pupils brought in by "politically correct" inclusion policies.
He also argued that attention needed to be given to what was taught, as the national curriculum was "turning off" many special needs pupils in mainstream schools.
Mr Gains is a member of a group of academics arguing for "responsible inclusion". He said inclusion policies had been framed "largely by political and ideological imperatives", and that there had been little research on what worked best.
Local education authorities re being stampeded into closing special schools, without such a policy being justified by research, the group says. Political priorities have taken over from informed debate when it comes to the inclusion of special needs pupils.
Mr Gains said official belief in full inclusion meant some children had been pushed into schools unable to meet their needs.
"The full-inclusion lobby has invaded all major channels of administration to such a degree that disagreement has been marginalised and individual doubts surpressed," he said.
"Countless thousands of children representing the vast range of learning difficulties are being 'shoe-horned' into mainstream schools with little or no help."
Mr Gain suggested that decision-makers were attracted to inclusion because it was cheaper than special school placements.