More than 100 of the country's best independent schools threaten to rebel against A-levels by signing up to a new, tougher exam which will cut coursework.
Details of the new Cambridge Pre-U exam were revealed after the Government's exam watchdog started softening its line on reducing coursework, one of the main bones of contention of the independent schools.
The 100 schools considering signing up for the new exam reads like a Who's Who of the independent sector, including Charterhouse, Dulwich College, Eton, Highgate and Winchester.
And 20 state sector institutions - mostly sixth-form colleges - have expressed an interest although they will get funding to submit their pupils for the exam only if it is given the green light by the Qualifications and Curriculum Authority, the exams watchdog.
University of Cambridge International Examinations, which is developing the Pre-U and is a sister organisation of the Oxford and Cambridge and Royal Society of Art exam board, is submitting it to QCA for approval and it was being stressed in government circles that the exam watchdog has already given the green light to one rival to A-levels, the international baccalaureate.
The new exam, which will concentrate more on essays and reduce coursework to a minimum, will be graded on a 10-point scale, with points nine and 10 being significantly more demanding than a simple grade A at A-level.
Students will be required to study three or four principal subjects, plus a subsidiary, and do an extended essay and global perspectives project (to give them some understanding of the international world). They will be presented with a diploma with a maximum point score of 50, 10 for each principal subject and five each for the essay and the global perspectives project.
Graham Able is head of Dulwich College and chairman of the joint academic committee of the Girls' School association and Headmasters' and Headmistresses' Association, representing almost all leading independent secondary schools. He said: "I have almost certainly signed my school up to start it when it begins, hopefully in 2008.
"There is growing dissatisfaction with examinations. Neither A-levels nor the international baccalaureate give us what we want."
He said A-levels were "lacking in stimulus", adding: "They are putting in things that are simply to be examined in little chunks but have little real value. We are wasting a lot of time doing coursework. It is doing simple things more mechanically."