The Conservative Party is setting up an inquiry into schooling in England for children with learning difficulties.
The Tories question the scale of special school closures
It says this reflects concerns about the closure of special schools, and shortcomings in a government audit.
It also wants to re-examine the process by which children with more severe needs are given "statements" detailing the help they should have.
The party has recently been criticised by organisations campaigning on behalf of children with special needs.
The shadow education secretary, David Cameron, said provision for children with special needs had not kept pace with the huge growth in their numbers.
"There is growing concern about the statementing process, with parents finding it is too bureaucratic and too adversarial," he said.
"The thrust of the government's approach is that all but those children with the most severe disabilities and learning difficulties should be educated in mainstream schools.
"This is leading to the closure of many schools for children with moderate learning disabilities (MLD schools). This is reducing choice for parents."
Mr Cameron said the recent review of the system by its original architect, Baroness Warnock, was "a stunning recantation".
"In her new document, she delivers commonsense observations that many of us know to be true. The pendulum has swung too far.
"The idea of inclusion has hardened from a helpful tool to ensure children were not shut out of mainstream, into an unbending doctrine that means children cannot get into special schools when they need it."
The government has promised an audit of needs. But this is limited to the most severe cases.
Mr Cameron said a wider-ranging commission was necessary.
"The committee has one purpose, and one purpose only - to find out what provision we really need to make", he said.
It will be chaired by Sir Robert Balchin, a long-standing party education adviser.
Among witnesses invited to give evidence are Lady Warnock herself and two parents of children with special needs who have been vocal critics of current policy: Julie Maynard and Maria Hutchings.
The approach of Lady Warnock, Mr Cameron and "a small group of parents" has been criticised in press adverts by organisations and individuals concerned with special educational needs.
They were accused of "undermining the inclusion of disabled pupils in mainstream schools".