Schools are already stretched to the limit by pupils with additional support needs (ASN) without the extra burdens likely to be imposed by new legislation, the Kirk asserts.
MSPs were yesterday (Thursday) set to approve Scottish Executive reforms but the Church of Scotland remains seriously concerned that primaries and secondaries will be unable to cope with more demands for mainstream schooling. Councils continue to worry about escalating costs.
In the Kirk's education submission to the General Assembly next month, it questions whether the presumption of mainstreaming can be maintained. Its outspoken comments follow a study it commissioned from the Scottish Council for Research in Education into inclusion practice in two primaries and two secondaries.
The education committee states: "The evidence suggests that all the schools visited were working to the limits of their capacity in respect of including children and young people with ASN.
"This raises serious concerns about resources, given the anticipated increase in the number of pupils with ASN being educated in mainstream schools. There are serious questions to be asked about the limits to which schools can adapt to special circumstances without jeopardising their capacity to respond effectively to the needs of all children."
The problem for policy-makers and local authority workforce planners, the Kirk says, is that many of the factors which can make or break successful integration for pupils with additional support needs depend on the "delicate ecological balance of the individual classroom".
Three of the four schools involved in the study, carried out over three months by Dr Anne Pirrie, had units or resource bases that provided for pupils with a range of needs. They spend most of their time there and the Church says that this raises "fundamental questions" about definitions of mainstreaming.
It backs units or bases which are at the heart of schools to provide a "safe haven" for particularly vulnerable pupils, who can consolidate their learning in class.
The head of one secondary, which is regarded as a centre of excellence for children with sensory impairments, noted the considerable rise in the proportion of pupils coming into school with social, emotional and behavioural difficulties, although they tended not to have a record of needs.
He was committed to inclusion but believed that some children were "so badly damaged" and disruptive that mainstream provision was not appropriate. Off-site provision was better for the most difficult and challenging pupils.
There were limits to what a large secondary could do to adapt to the needs of a small minority of pupils with poor attendance and histories of violent antisocial behaviour.
The head of another secondary had one pupil with attention deficit hyperactivity disorder (ADHD) who spent all his time in the support base because of his extremely disruptive behaviour. Some teachers felt he was more isolated than he would have been in a special school. They also questioned the cost of the individual attention he required at all times.
In one of the primaries, in an area of multiple deprivation, only one child had a record of needs but 14 had individualised educational programmes (IEPs). In a primary 1 class, four out of 20 children had moderate learning difficulties related to "poor oracy".
The headteacher reported "huge aggression in the community".