In a lecture sponsored by the Scottish Liberal Club in Edinburgh at the weekend, Baroness (Veronica) Linklater of Butterstone delivered a remarkable broadside at her party's members in the Scottish Executive coalition, claiming their policy condemned many children to "an educational experience which is often inadequate and at worst actively damaging".
Many children are being placed in schools, particularly at secondary level, which "provided a learning environment that is inappropriate for them - because of its scale and because, within its normal processes, individual needs cannot be accommodated".
Lady Linklater is founder of a boarding school in Butterstone, Perthshire, catering for the "educationally fragile". The New School's pupils may be affected by dyslexia, dyspraxia, autism, elective mutism - or a phobia about attending school. Ironically, an HMI report last year found learning support and the implementation of legislation on special needs to be no more than fair.
While attending mainstream schools, the New School's pupils had all experienced some degree of teasing and sometimes significant bullying, as well as a complete lack of inclusion in the general life of the school, Lady Linklater claimed.
She said: "Their experience had been a miserable one in social terms. This had led to a loss of self-confidence which in turn made learning impossible. They were significantly underperforming in relation to their potential. For them, mainstream was exactly the opposite of inclusion."
The number of special schools in Scotland fell from 195 in 2000 to 189 in 2002 but rose again to 192 last year. An estimated 14,000 children - 1.9 per cent of the school population - receive extra support in school because they are deemed to be affected by learning and communication difficulties or significant physical disabilities.
Around half of these children are, however, being educated alongside other children in mainstream rather than in schools dedicated to their needs.
Lady Linklater also issued a warning about the funding required to implement the additional support for learning legislation from next year, which she said would increase the proportion of pupils requiring support to 4.2 per cent.
"We will wait with bated breath," she said. "I just wonder how resources are to be found to encompass that 4.2 per cent - and what will be lost for the current 1.9 per cent of children deemed to have special educational needs."
She also suggested that parents are desperate to get their children into mainstream. "In the process, they are denying there is a difficulty - just because it is so painful for them. Professionals should be encouraging them to face up to reality - and to accept and love their children as they are."
Judith Gillespie, development manager of the Scottish Parent Teacher Council, told The TES Scotland: "Many parents have been brainwashed into thinking that, if their child with special needs can go to a mainstream school, they will become like the other children there. This is quite clearly unrealistic.
"Many need a total package of support - a stimulating and safe environment with specialist services such as therapists close at hand - that can only be provided in a special school, or in a unit separate from mainstream."
Lady Linklater has a daughter diagnosed with DCD - developmental co-ordination dysfunction - a condition with traces of the communication disorder Asperger's syndrome and the movement disorder dyspraxia. Her daughter's negative experiences of mainstream provision spurred her on to found the New School.
The Executive stresses that a "presumption" of mainstreaming is just that.
"Ministers continue to support a range of educational provision and special schools are a part of that," a spokesperson said. "The child's interest is paramount and parents can make a placing request for the school which they believe best suits their child."