Failing to improve schools has seen Oxfordshire County Council downgraded for its performance.

The serious lack of progress in the county's state schools was spelled out by the Audit Commission as it stripped County Hall of one of its highly-prized ranking stars - demoting it to three.

Oxfordshire was one of just two councils to drop a star, out of 19 assessed in the South East.

The other was Slough Borough Council.

Oxfordshire is now at the bottom of league tables comparing exam and test results with similar affluent counties.

School performances were last week highlighted as a worry by new education director Janet Tomlinson.

County council leader Keith Mitchell said: "Educational attainment is vital for our children and we were conscious before this inspection that many Oxfordshire schools are not yet doing well enough.

"My two feelings are disappointment that we have not done better on the attainment issue and determination to improve our performance for our children and get our star back double quick."

The commission's district auditor, Maria Grindley, said: "As a council, it is fair to say there have been improvements in many areas. But it is the issue of examinations and educational attainment that has affected its star rating."

Council chief executive Joanna Simons told councillors: "We know that this will come as a shock to many staff and it will be hard to understand why we have gone down.

"The reason our performance assessment score has dropped relates to our rating for children's services, which has gone down from three to two. This is largely due to school exam results."

Mrs Tomlinson last week feared some heads were in denial about consistently disappointing GCSE results, adding that children had a better chance of acquiring a good GCSE result in Slough.

This year's figures for Oxfordshire showed 57 per cent of pupils achieved five GCSEs at grade C or better, compared with 69.2 per cent in Buckinghamshire and 64 per cent in Gloucestershire.

Her assessment was welcomed by Open University Professor of Education Bob Moon, who said he expressed similar concerns two years ago.

Prof Moon, a former head of Peers School, Littlemore, said many youngsters were "getting a poor deal", with schools still reluctant to embrace changes that had been shown to work outside the county.

Prof Moon, who lives in Oxford, insisted measures to bring about better results were "not rocket science."

He said all schools should have computerised systems to monitor the progress of pupils approaching GCSEs, along with more advice to parents on the organisation of revision and homework.