Including children with special educational needs in mainstream classrooms can be "a form of abuse", a professor of education has said.
Children with special needs are far more likely to be excluded
John MacBeath of Cambridge University was commenting on a report he co-wrote for the National Union of Teachers.
NUT general secretary Steve Sinnott called for an audit of provision around England as a step towards addressing "major areas of policy failure".
But ministers said children were taught successfully in a range of settings.
Schools Minister Andrew Adonis said: "We put the needs of the child first."
The Cambridge report, The Costs of Inclusion, said teachers and teaching assistants were often going "beyond the call of duty" to help children with special educational needs (SEN).
It cited examples of staff emptying tracheostomy tubes or changing nappies, often lacking the appropriate training.
From the child's perspective, unmet needs could result in extreme behaviour.
Prof MacBeath told journalists: "Physically sitting in a classroom is not inclusion. Children can be excluded by sitting in a classroom that's not meeting their needs."
The typical secondary school timetable - rushing from physics, to history then French, say - was for some children as bewildering as being "on another planet".
"You might call it a form of abuse, in a sense, that those children are in a situation that's totally inappropriate for them."
He and co-author Maurice Galton stressed their report was not "anti-inclusion", a point echoed strongly by leaders of the NUT, traditionally the most pro-inclusion of the education unions.
"In general teachers are positive towards the principle of inclusion," they said.
They believed it was good for children who would previously have been in special schools to be included in mainstream schools.
But also their classmates learnt "important lessons about diversity and tolerance".
What concerned teachers was whether schools could provide a suitable education for those with complex needs.
Lord Adonis said children should be taught in mainstream schools if their parents wanted, and if it was "not incompatible with the efficient education of other children".
"We also want pupils for whom this is not an option to benefit from high quality education and for strong links to be forged between special and mainstream schools so pupils can mix with their peers," he said.
But Mr Sinnott said the ideal was often not borne out by the reality.
He said the NUT had drafted an amendment to the Education and Inspections Bill - currently going through the Commons - to outline the range of services local authorities should provide, including those for special educational needs and behaviour support.
He told BBC News he thought an audit of current provision would be a good starting point, because of the way practice varied between different areas.
And he believed "very, very strongly indeed" that there should be a halt to special school closures.
"There's a need for an urgent review of inclusion in policy and indeed in practice," he said.
Mr Sinnott questioned the way disability discrimination legislation obliges all schools to accommodate all children.
"You would have to, if you were a parent, question whether the local school could meet the needs of your child," he said.
Shadow education secretary David Willetts said the government should radically rethink its inclusion policy.
"The obsession with inclusion is unfair on children with special educational needs, unfair on the rest of the class and unfair on teachers," he said.
A spokesman for the Department for Education and Skills said it would not review the strategy it was currently implementing.
But it would take into account the NUT report, along with the Commons education and skills committee report on SEN due to be published in June.
The National Autistic Society said most of the 90,000 autistic children had to learn in mainstream schools as there were just 7,500 specialist places.
The society's head of education, Mike Collins, said: "When teachers do not know how to best support a child with the disability the whole class is affected, and the child is unable to develop to their full potential."
The Costs of Inclusion by John MacBeath, Maurice Galton, Susan Steward, Andrea MacBeath and Charlotte Page, published by University of Cambridge Faculty of Education.