Headteachers are being urged to face the "stark and uncomfortable fact" that in GCSE pass rates, Oxfordshire is being outperformed by deprived areas in big cities.

The county's former chief education officer, Prof Tim Brighouse, and an ex-headteacher of Oxford's Peers School, Bob Moon, have warned heads that their attitude towards GNVQ qualifications could be stopping many teenagers from getting good grades.

Their comments follow the publication last week of league tables, which showed that 54.4 per cent of the county's pupils achieved the required five or more A* to C passes at GCSE -- well below similar authorities and behind Birmingham (56.4 per cent) and London (55.2 per cent).

Some heads blamed the county's poor performance on their refusal to boost results with GNVQs, which they branded "soft options", which attract up to four times the number of league table points of a GCSE, depending on a student's performance. Prof Brighouse, chief adviser to the London Challenge -- a scheme to improve standards in the city's schools -- and Prof Moon, who works for the Open University, said: "Their stance, and we appreciate this will not be true of all heads, if true, has stopped countless youngsters from obtaining qualifications which are motivating and a valuable component of any career profile.

"The stark and uncomfortable fact is that over the last 15 years or so, the performance of Oxfordshire schools has risen from 35 per cent gaining five or more higher grades to today's figure of just under 55 per cent."

They said that over the same period, the figure in London had gone from 10 per cent to 55 per cent and that Oxfordshire could do better, with and without GNVQs.

Rod Walker, head of Witney's Henry Box School, and the present head of Peers, Lorna Caldicott, were among those uneasy about schools offering GNVQs. Mrs Caldicott said: "Peers hasn't gone down the route -- we're looking for real improvement and we're already seeing signs of it."

Mr Walker said: "I would not retreat from my position but, that said, I would agree there should not be snobbery about GNVQs. These subjects are important. The issue is whether they should be equivalent to four higher GCSE grades."

Cynthia Bartlett, head of Bicester Community College, said: "I would expect children to get a broad range of subjects. We're not here to boost Government statistics -- we're here to educate children."