Schools have been accused of failing to meet the aspirations of working class and ethnic families by allowing middle class parents to dominate their governing bodies.

The imbalance means many parents do not feel part of the life of the school which then impacts on the attainment of their children, according to a Midland-based study.

Research led by Professor Stewart Ranson, from the University of Warwick's Institute of Education, praised the "profound contribution" made by middle class parents to schools.

But it warned: "We are at a new stage of development. Schools need to connect with their communities.

"Arguably, schools will not become effective learning communities until they become truly cosmopolitan learning communities, and they will only realise that vision when democratic governance is strengthened at the level of school and community as well as the local authority."

The controversial paper, to be published in the Education Review, is likely to be greeted with anger by governors from professional backgrounds.

Most give up their personal time, using their experience and expertise on a voluntary basis to help improve their local schools.

While acknowledging the contribution they make through "access to privileged networks and resources", Prof Ranson claimed that was only half the story.

"Schools tend to think that parents who are involved in middle class professions have the social capabilities, contacts and connections that will be of use to the school," he said.

"But this neglects the skills and capabilities and knowledge that ordinary mums and dads have in the estates.

"By involving all parents that will motivate all youngsters. The challenge to engage and interest youngsters in their learning requires the involvement and inclusion of all parents and their communities."

The practice of recruiting members of the public to help run schools started in 1988 when the Conservative government created more than 400,000 "volunteer citizens".

The Warwick report describes the movement as the "largest democratic experiment in voluntary public participation" ever.

But it expresses concern that then, as now, those recruited were "generally white, middle-aged, middleclass, middle- income, public/ community service workers".

In Birmingham, for example, only four per cent of governors are from Pakistani or Bangladeshi backgrounds, despite this group making up about 18 per cent of the population.

Prof Ranson stressed if schools were to be truly democratic, they needed to ensure all parents felt valued and included.

"It is the valuing and reacting to parents' communities that is key to supporting youngsters in their learning." The study claims engaging parents was equally as important to raising standards as setting attainment targets and monitoring pupil progress.

Schools that have been successful in reaching out to the wider community have done so by creating mechanisms such as parent forums and people councils.

Other methods involve setting up projects involving parents, asking parents to work as mentors and holding adult courses on the school premises.