Special schools in England could become "selective" if performance tables on special educational needs (SEN) are published for the first time, campaigners have warned.
Ministers have announced plans to make public details of the progress of the lowest-achieving 20 per cent of pupils as a way of helping parents to judge schools. The proposals were included in the SEN green paper, published this month by the Westminster Government.
Organisations representing SEN teachers say the introduction of the tables would lead to special schools being ranked, which could in turn lead heads to reject children with severe needs.
The tables would show the achievements of children working below standard national curriculum levels and their "progress" in P-scale data, which is used to show the achievements of children who are working below level 1 on the normal scale of achievement.
Special schools have had to submit P-scale data to the Department for Education for the past two years, but to date the information has not been made public.
Lorraine Petersen, chief executive of the National Association for Special Educational Needs, said there was a risk that data would be "misinterpreted".
"Parents might think they can use them to select a school for their child in the same way as they would for a mainstream primary or secondary," she said.
"P scales are not meant to be about assessment, they are a snapshot of a child's progress. In some schools half the pupils can be absent because of hospital stays and a league table might not be able to explain this.
"This could lead to special schools becoming more selective," she added, "especially if they are asked to take a child with complex, overlapping needs.
"The potential for this is even greater because of the introduction of academies and free schools," Ms Petersen said.
But David Bateson, chairman of the Federation of Leaders in Special Education and principal of Ash Field School and Assistive Technology Assessment Centre in Leicester, said teachers should not be worried.
"Heads are happy to be helpful and transparent. Special schools would be interested to know if colleagues down the road were doing a `better' job."
A DfE spokesperson said: "Progress measures have been introduced for all schools, so that they are no longer measured by an arbitrary target of five A* to C but by how they help those with complex needs to progress. Publishing more data is designed to give families more information about schools in their area."
Politicians first attempted to make public the school performance of children with SEN 10 years ago. An average point score was included in league tables so their key stage 2 test results could be "quantified".
Pupil progress has also been introduced to league tables by using the CVA "contextual value added" score for each school.