Parents say some education authorities are getting round their duties by telling parents the Government's Green Paper on special needs means they do not have to specify children's needs or what services they should get.
Currently, the formal statements of special educational need must identify both the child's needs and how they will be met.
Consultations on the proposals resulted in more than 3,500 responses, and the Government is still considering its next move.
The Green Paper upholds the principle of statements, though it does look at how responsibility for special needs work is divided between schools and education authorities.
Dr Katy Simmons, co-ordinator of the Independent Panel for Special Education Advice, said: "There are local authorities making it up as they go along and justifying it by reference to the Green Paper.
"One said it didn't have to specify what a child's needs were on the statement. I have referred it directly to Estelle Morris, the education junior minister."
Margaret McGowan, an advice worker with the Advisory Centre for Education, added: "One caller told us that her education authority had said it was no longer their policy to detail specific provision on statements. Parents should know that the status of the Green Paper is that of a discussion document."
Both groups are also challenging suggestions that the rising number of children with statements represents unnecessary and expensive bureaucracy.