Colleges that take in school pupils are more concerned with increasing recruitment than widening participation, according to an Association of Colleges survey.
An association request for examples of colleges' work with pupils aged 14 to 16 - many of them excluded or disaffected - discovered commercial motives outweighed educational ideals.
Asked to list the advantages of such courses, two thirds of colleges said they helped to "secure more clients for college at post 16". Only a quarter said they might "widen participation" - the hopeful title of the report - and just one in six said they were an opportunity to develop staff expertise with a different client group.
Lack of funding was the chief disadvantage listed by the 45 colleges which responded, followed by pressure on resources and staff time and behavioural difficulties presented by some of the students.
One college said: "The vocational element and change of environment motivates this group (disaffected students) but it would equally motivate all pre-16 students... further education could be wrongly perceived as the place for disaffected students or those lacking ability."
Another commented: "If widening participation is to succeed for pupils who would normally attend school then funding issues need to be sorted out, whether through schools or the Further Education Funding Council."