Several top independent schools in Oxfordshire have revealed they may ditch A-Levels within two years for a new diploma.

Magdalen College School, Oxford, Oxford High School, Radley College, Abingdon and Abingdon School are among those interested in the 'Cambridge Pre-U' being developed by the University of Cambridge International Examinations (CIE) for independent schools only.

State school heads, worried the diploma could give private school pupils an unfair advantage in university admissions, have condemned the move.

Last year, the percentage of students passing A-Levels reached 96.2 per cent, with almost 23 per cent achieving A grades. The Government is considering introducing measures to help differentiate between high-flying candidates, although Andrew Hallsok, head of Magdalen College School, said these would not restore confidence.

Students taking the diploma would study three main and one subsidiary subject, and complete a degree-style project. If all elements were passed, the diploma is awarded, if not, the individual subject qualifications.

Mr Halls, pictured, said: "We would be taking a big risk by ditching A-Level but it is not an exciting exam any more.

"It's about being able to stretch the most able, show rank order and differentiate between candidates, but it's also about the level of excitement. It will demand complex thinking from pupils rather than digesting notes for exams."

The International Baccalaureate diploma, which state schools can offer, was once a hot favourite to replace A-Levels but cost and the idea that it restricts choice has resulted in few schools switching.

But Rod Walker, head of Henry Box School, which has topped the league of county state schools at A-Level four years running, said he would strongly oppose any exam which excluded state schools.

He said: "I'm staggered that this is being proposed. We would want to continue to feel we are competing on equal terms with the best independent schools."

Oxford High School head Felicity Lusk added: "The Pre-U is a very good alternative to both A-Levels and the IB and we are going to be looking at it very seriously."