Lack of regulation could lead to responsible firms which have long provided worthwhile classroom resources being undercut by marketing-orientated companies plying teachers with heavily-branded materials of dubious educational value.
But the claims, made at a conference on business involvement in schools at the London Institute of Education, were rejected by Susan Johnson, from the Department for Education and Employment.
She said the DFEE opposed any exploitation of pupils and was reviewing the current voluntary guidelines for schools produced by the National Consumers' Council.
Sheila McKechnie, the Consumers' Association director, told conference delegates: "This government is in love with the corporate sector. They are not getting a grip on their role in terms of the good of our children and the future of our education system. My fear is that for all the rhetoric - the softly, softly, we want business and the third way - the DFEE will back-pedal on the issues that are absolutely central to this debate and to pupils having an education at school, not propaganda."
Schools are beginning to use branded resources without considering their appropriateness. The DFEE is not checking to see if guidelines are being used or if "unacceptable bits of marketing" are getting into classrooms, she said.
She added that parents are generally positive about business involvement in their children's schools, citing association research based on interviews with 1,000 parents nationwide.
But they had little or no awareness of the voluntary guidance available to schools, and assumed there was some kind of external control on the materials going into classrooms. When told this was not the case, nine out of 10 said they would favour active government endorsement of guidelines.
But Susan Johnson, who manages the DFEE's business and community links, said: "There can be educational benefits from involving young people in market research. Handled properly it can give them an insight into the business world.
"In accepting branded materials, headteachers and teachers need to take a pragmatic approach and weigh up the value of the materials. It would be naive to think we can shelter pupils from the commercial world. Put in context and properly explained, no one need be exploited by branded materials in schools. "