Tanni Grey-Thompson OBE, paralympic hero and four-time winner of the London Marathon, is a familiar face on prime-time television.

The Rt Hon David Blunkett, a man who has been blind from early childhood, is now Home Secretary. He has been referred to in some quarters as a future Prime Minister.

While most disabled people continue to pay a heavy penalty, and struggle to catch a bus let alone find employment, the past two decades have seen momentous changes in attitude.

And schools have played their part. It is 21 years since the 1981 Education Act introduced the concept of “special educational needs” and started to move children with cognitive or physical disabilities out of special schools and into ordinary classrooms. Ms Grey-Thompson was able to attend a mainstream secondary because her parents armed themselves with the 1978 Warnock Report and the 1981 Act that followed.

It is now accepted that, wherever possible, children with disabilities should be educated alongside their neighbours and, for the first time, the majority are to be found in mainstream schools. Around 87,000 - 1.5 per cent of five to 15-year-olds - remain in special schools.

In many ways, the wind is set fair for further progress. The drift of European legislation is strongly in the direction of new rights for vulnerable minorities. In Britain, ministers have said that inclusion is desirable on “strong educational as well as social and moral grounds”.

The Government established its Social Exclusion Unit (although it says comparatively little about special needs) and the Disability Rights Commission has got into its stride. Money has been put aside for further integration in schools including cash from the Standards Fund and an additional pound;220 million Access Fund covering 2001-2004.

And this month inclusion gets another boost with a new code of practice for schools, the result of last year’s Special Educational Needs and Disability Act, which aims to ensure that schools do not discriminate against disabled pupils.

Yet, if the 1981 Act has come of age, there is little celebration. For the first time in two decades inclusion looks like grinding to a halt. Even the most forward-looking heads say they are under attack from targets and declining behaviour standards. The pressure to exclude is starting to match the pressure to include. As a result, the number of children moving from the special to mainstream sector is dwindling almost to nothing.

Children with moderate learning and modest physical impairments are continuing to move out of special schools, but as they do so, their places are taken by the rising numbers of children with behaviour problems, including autistic spectrum and attention deficit disorders.

As this shows, the terms of the debate have changed. Inclusion is no longer a matter of installing ramps, a lift, or even a sluice room for incontinent children. It now means taking on disruptive pupils. And the evidence is that schools are saying “no”. Permanent exclusions rose by 11 per cent last year, and pupils with special educational needs were three times as likely as others to be among them.

After 20 years of progress, John Bangs, assistant general secretary of the National Union of Teachers detects an important change in attitude. But further progress, he warns, will be difficult while schools feel they are under the cosh. There is a danger the process will go “into reverse”.

“The main problems are emotional and associated learning difficulties that lead to challenging behaviour. Kids with severe learning difficulties can be extremely problematic,” he says.

“I think there’s a feeling that the closure of special schools has challenged teachers. There’s an understanding that there’s got to be support and provision for kids with emotional and behavioural difficulties if you’re going to include them in the mainstream classroom.

“The enormous pressure in terms of targets, testing and expectations means you simply can’t halt the class to spend a lot of time with an individual child. These extraordinary pressures are contributing to higher exclusion, and a less relaxed attitude to kids disrupting your class.”

Cash is at the root of the debate. Schools with strong records of including disabled children say there is a great deal that can be done with better training, know-how and an open mind - provided that extra funding is available.

It is often argued that teaching a child in a mainstream classroom is actually cheaper than providing a place in a special school. Which is true if the special school could be abolished. But what makes life difficult for education authorities is an insistence on the part of some parents that their children are too vulnerable for a 1,000-plus comprehensive, which may not be properly adapted, and that they require the small classes and safe atmosphere of a different sort of school. Many fear bullying.

It is significant that the disability rights movement has now identified disruptive behaviour as a key issue, and it was a major topic at the inclusion summer school held recently at Nottingham University.

Organisations like Disability Equality in Education and Parents in Partnership maintain that children with cognitive or emotional problems should be treated no differently from those with physical impairments, and should be included as a matter of course. If schools have a difficulty with certain categories of child, they say, the education system should adapt - by lifting the regime of targets, training staff better or by spending on additional teachers.

For 20 years the Centre for Studies on Inclusive Education, has been at the forefront of the campaign for the abolition of special schools. Mark Vaughan the founder argues that educating children separately is a breach of their human rights. Although it will probably be a generation before this is accepted, education policy-makers should start from that principle and factor in the pupils it might otherwise seem convenient to ignore. After all, he says, some schools manage with the most disruptive children.

Some schools, they point out, do notably better than others. In their book Can Effective Schools Be Inclusive Schools? Professors Ingrid Lunt from the Institute of Education and Brahm Norwich, now at Exeter University, found that only 42 secondaries in England and Wales combined high levels of integration with high achievement based on GCSE results.

Professor Lunt is now conducting a further study to identify the characteristics of these schools in the hope that others can copy their example. Many will probably struggle if, as she suspects, a stable workforce and pupil population are important factors. None of the 42 identified serve an inner urban area.

THE DIFFERENCE AN ACT CAN MAKE

Last year’s Special Educational Needs and Disability Act amended the 1996 Education Act and the 1995 Disability Rights Act, with two main results.

Firstly, it sharpens up the code of practice for special educational needs which should result in faster identification and more effective teaching. Secondly, it reduces the grounds on which a school or local education authority can refuse to admit a disabled child. The “efficient use of resources” is no longer a ground for rejection. Instead, a school must contend that admitting a child will prejudice the “efficient education” of other children, or that building alterations required would be so expensive as to be “unreasonable”. There is also the new code of practice covering discrimination, although this does not in itself impose new duties and is mainly illustrative.

While most people believe it will further the cause of inclusion, the question is, by how much? Certainly it should help stamp out the more outrageous instances of backsliding and obstruction by schools and education authorities. Disability rights activists are now represented on the renamed Special Educational Needs and Disability Tribunal. And the tribunal’s decisions have been made binding. The changes should also give heart to severely impaired child such as those with cerebral palsy who, aside from mobility problems, may also have serious communication difficulties. Schools which are used to accepting children dependent on wheelchairs will probably be asked to take on a greater range of need.

But there are important caveats. Whatever the talk about“rights”, the legislation continues to insist that any course of action must be judged “reasonable”, which in practice is very often translated as “affordable”.