A dramatic increase in the number of independent schools ditching GCSEs is revealed today in figures showing their exam results.
They show a 33 per rise rise in the number of entries for the rival IGCSE - based on traditional O-level lines and considered by many heads to offer a better preparation for tackling A-levels in the sixth-form.
The numbers rose by 33 per cent this summer to 129,288 - thus accounting for 32 per cent of year 11 exam entries. GCSEs, in comparison, fell from 293,335 to 274,183.
Barnaby Lenon, chairman of the Independent Schools Council, said he could see "no signs" of the switch towards the IGCSE abating, adding: "I don't think there is any evidence that it has reached its peak."
Nationally, this year's IGCSE figures were inflated because a number of schools - both state and private - ditched GCSE English in the wake of last year's controversy when the grade boundaries were raised between sittings. A number of state schools hedged their bets by putting their pupils in for both sets of exams in order to stand a better chance of obtaining C grade passes to boost their league table rankings.
Mr Lenon said the drift towards the IGCSE started with maths "because of unhappiness with GCSE coursework" and the moved to science.
"It was felt that the IGCSE was a better preparation for A-level," he added. "The syllabuses had a bit more content and were slightly more demanding. Those arguments still apply."
Initially, he added, some schools were reluctant to enter their lower sets for the IGCSE on the grounds that it might be too demanding for them - but that worry appeared to be disappearing.
"It will be interesting to compare the results of those who opted for their pupils to take both exams," he added. "That could determine what they do in the future."
Some private schools have opted to devise their own exams as an alternative to the GCSE - such as Bedales, an independent co-educational day and boarding school in Petersfield, Hampshire - where the main two avenues at 16 for pupils are the IGCSE and its own assessed courses.
From this September, it will be possible for the first time for pupils to abandon GCSEs altogether as they will take exams in the core subjects of English, maths, science and a language in IGCSEs while they can opt for the school's assessed courses in subjects like English Literature, Ancient Civilisation, history, geography and outdoor work - such as assembling a Land Rover.
This year's cohort was split almost equally between taking the GCSE, IGCSE and Assessed Courses Next year, though, it is expected around 55 per cent will take IGCSEs, 40 per cent Bedales Assessed Courses and just five per cent GCSEs.
Keith Budge, its headteacher, said: "Bedales has a history of educational innovation. The replacement of some GCSEs with our own Bedales Assessed Coursers has, I believe, not only created a better platform for A-level success but also led to more success with offers from prestigious universities as these courses are not only more imaginative and motivating but also offer a more academically stretching curriculum."
Overall, this year's independent school year 11 exam results - combining GCSE and IGCSEs - show the proportion of A* grades awarded has risen from 31 per cent last year to 32 per cent in 2013 at a time when the national results showed a decline from 8.3 per cent to 8.2 per cent.