Local authorities and regional development agencies are overriding government, and their own, brownfield development policies by encouraging developments on green-belt sites, campaigners have claimed.

Towards Sustainable Economic Development, a report launched this week by the Council for the Protection of Rural England, says: "Huge overallocation of [greenfield] land is undermining attempts to promote an urban renaissance and tackle social exclusion." The report details nine case studies from around the country of good and bad practice in planning for economic development.

Neil Sinden, the CPRE's head of planning and local government, said: "A glut of greenfield sites makes it more difficult to steer economic investment to where it can tackle pockets of high unemployment, secure urban renewal and reduce the need to travel by car." In several case studies, local authorities offered planning permission on greenfield sites even where they contradicted their own policies of promoting brownfield development.

For instance, the stated aim of planning policy in Brighton, East Sussex, is to reuse land within the town so as to avoid encroaching on the South Downs, a designated area of outstanding natural beauty. Yet East Sussex County Council proposed a "high-quality business development" on a greenfield site within the South Downs designated area that was approved by the DETR, and Brighton and Hove Council supported the development of a new football stadium in the designated area.

In other case studies, greenfield sites given planning permission for industry or business did not lead to new employment but to blighted land.

Hereford and Worcester County Council, for example, approved a 30 ha business park in Bromsgrove green belt in 1992, with the aim of creating 3300 jobs. To date, just two industrial developments have been built, providing only 200 jobs.