Campaigners trying to save Thrupp lake at Radley near Abingdon from being used as dump for spent fuel ash have suffered a major set back.

Ruth Kelly, the Secretary of State for the Communities and Local Government, has said she will not "call-in" a planning application to pump the ash from Didcot power station into the old gravel pit.

The group was hoping for a public inquiry into RWE npower's plans to pump half-a-million tons of ash into Thrupp lake until the coal-fired power station closes in 2015. Once the site is restored it will be designated as a wildlife area and maintained by a trust.

Mrs Kelly's decision means that once conditions and legal agreements have been finalised and signed, planning permission will be issued by Oxfordshire County Council.

Permission was granted in July but objectors wrote to Mrs Kelly asking her to call-in the application and examine the issues in detail through a public inquiry.

Save Radley Lakes activist Marjorie White said: "We are deeply disappointing but the fight to save Thrupp lake from being destroyed is by no means over and we will explore other options.

"We have made a complaint of maladministration against the council over its handling of the planning application and this will now be investigated by the Local Government Ombudsman."