This debate has always been emotional and polarised. No parents want their child set apart. For some, only a mainstream school will do. Other parents - and many teachers who have to balance the needs of the class - fear that mainstream schools can’t give every child the attention they require.

But, unless we are honest about the issues, we won’t find the best solutions. That means distinguishing between those with physical disabilities and moderate learning or behavioural problems, and those who have severe emotional, behavioural and social problems (now called EBSD).

No school should turn a child away for want of wheelchair access, Braille translation, or suitable loop. And good special needs assistants can help overcome most learning difficulties. There has been extra cash for such provision. Mainstream schools have also started to use the expertise built up by special schools, which traditionally catered for their needs.

The Special Educational Needs and Disability Act 2001 has strengthened the right of these children to be educated at a mainstream school. However, many young people with severe forms of EBSD need alternative provision.

If the Government’s commitment to “personalised education” is to mean anything, every child must have an education appropriate to his or her needs. And if they simply can’t cope with mainstream education, despite the best support, we must offer the right alternatives. Unless we do so, we not only fail them, we also fail their classmates whose chance to learn is constantly disrupted.

Recognising this should not place teachers beyond the pale. When Charles Clarke announced his latest SEN drive in February, he promised “a continuing role for special schools”. Special school numbers have not declined enormously under Labour: there were 97,700 pupils in 1999 and 93,880 in 2003 in maintained and independent special schools.

Around a tenth of those being placed in mainstream schools are going to specialist units attached to the schools, while a quarter of children with statements are still placed in special schools. But in the same period, the numbers in pupil referral units has risen from 8,260 to 12,010. Some of those new pupils in PRUs are shunted from one exclusion to the next, having little chance of a decent education.

While some secondary schools can and do provide excellent support, many with spare capacity struggle with a host of other problems. And while the quality of PRUs has improved, there are not enough long-term places for pupils with severe problems.

We now need extra specialist provision. Of course, effective programmes can be expensive. But earlier identification is already saving money by overcoming less severe special needs early on. Thanks to assessment and a less rigid system of financial support for schools, the number of children given statements fell from 35,650 in 1997 to 30,720 in 2002.

The Government doesn’t seem to know how the pound;1.7 billion a year being spent on SEN in mainstream schools is being distributed. Such data should be collected as part of the annual school census. Then we could discuss what is needed and how to fund it.

Too many EBSD special schools had an appalling record - the Office for Standards in Education still reports that teaching is unsatisfactory in a fifth of such schools. We need new types of special school and more specialist units. This requires a new approach from ministers and teaching unions. The Government should promote and fund small special schools and units for those for whom mainstream is ineffective.

And the NASUWT should champion integration for those who would have been wrongly isolated in special schools in the past and who are succeeding in mainstream education.

Conor Ryan was special adviser at the Department for Education and Employment, 1997-2001