Eighteen-year-old Simon Bourne has applied for an engineering degree course at Cambridge University next year. He is expecting to be asked for “at least” three A grades among his five A-levels, if the university’s dons decide to make him a conditional offer in the first place.

A tall enough order, most would think. But if Bourne were applying in a couple of years’ time - he might be facing a much higher hurdle, and one couched in terms of grades and qualifications that don’t even exist right now. If he were applying in, say, 2010, “I might expect to be asked for three A* grades at A-level,” said Bourne, head boy at Warminster school in Wiltshire, where a boarding place costs about £19,500 a year.

Next autumn, for the first time, a tougher A-level will come on stream, with a new A* grade to try to pick out the high-flyers. Ministers are revamping the exam system for sixth-formers in the face of long-standing complaints that A-levels are just too easy.

Last year top private schools – including Eton, Dulwich and Harrow – turned up the heat in the fight for tougher exams. The threat was that some of our best schools would switch to rival qualifications such as the International Baccalaureate (IB) diploma or even the PreU, a new exam being developed in Cambridge.

Forty years ago fewer than 10% of A-level passes were A grades, this summer more than a quarter were. Gifted private and state school pupils are losing places at top universities, because dons find it impossible to choose between the thousands of teenagers all predicted to get a hat-trick of A grades.

Over the next few weeks head teachers will make a final decision about which syllabuses their sixth forms will offer from autumn 2008. But despite last year’s rumblings, it looks likely that most private schools will, after all, stay within the national exam system, reassured by A-level reforms which include the new A* grade as well as stiffer questions.

Geoff Lucas, secretary of the Headmasters’ and Headmistresses’ Conference (HMC), which represents about 250 leading private schools, confirmed: “Most fee-paying schools are sticking with the A-level for now.

They are taking a cautious wait-and-see approach to the reforms.”

A survey of 100 private schools reveals that nearly nine out of 10 say they will offer A-levels next autumn. Only 12% will teach the IB and just 3% the PreU, which places greater emphasis on essay writing.

Fears of an exam system in melt-down or of an educational apartheid, with state schools doing A-levels and private ones opting for the elite qualifications of IB and the PreU, seem to have been allayed.

Over at Cambridge University, where dons this summer turned away thousands of teenagers with three A grades at A-level, the admissions director, Geoff Parks, said: “I think ministers may have saved the A-level’s bacon. But a lot will depend on how the changes to the exam play out.”

At Eton college the head master, Tony Little, said that the issue of what to teach next autumn was still being debated. “If we do introduce some PreU qualifications it will be in a mix and match way, [alongside A-levels and only for some subjects]. We will not go the whole hog,” he said.

Richard Cairns, the headmaster at Brighton college, is “sticking with the revised A-level. The exam boards have listened to our concerns about the lack of stretch for the most able and are introducing tougher questions and a new A*,” he said.

“Our brighter pupils will be properly challenged and universities will have a system that discriminates properly. Given these reforms, most private schools will stay with the A-level.”

Cairns added: “Most of us believe private schools should work within the national examination system and campaign for change from within. It would be sad were our leading schools to abandon the mainstream.”

Cairns believes that the move by ministers to tighten up the A-level will also slow the steady trickle of private schools that have introduced the IB diploma in recent years. There are now 45 private schools and 56 state ones offering the qualification, but most, including Warminster – where about a third of the sixth form are studying for the IB – offer it alongside A-levels rather than instead of them.

“Only two of the top 100 schools in England are IB-only schools,” says Cairns.

But if they are few in number, they are also sure they have made the right choice. Graham Lacey, the deputy head at IB school Sevenoaks in Kent, thinks that the tweaks to A-levels will not solve its underlying problems.

“I do not think the reforms will make much difference to the fact that the qualification is increasingly being devalued,” he said. “We made the right decision to switch to the IB eight years ago partly because we were disappointed with the changes being made to the A-level then.”

The IB, he says, is a better discriminator of the best and brightest.

“It is an increasingly attractive qualification for top universities, which are becoming more familiar with it. Only 0.4% of students score the top mark of 45 points at the IB, while 25% of students get three A grades at A-level.”

At Warminster it’s a debate that is being fought out within the 470-pupil school. While Simon Bourne is sure that his choice of A-levels will prepare him well for the engineering degree he wants to do, Warminster’s head girl, Tzuki Stewart, who has applied to Oxford University to study English, is just as convinced that her IB course, which includes six subjects, will “open more doors”.

Who’s right? Only time will tell. But one thing is certain: if the A-level’s reputation isn’t revived by next autumn’s reforms, the grumbles and threats to switch to rival qualifications will start all over again.

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