Indeed, Mr Tomlinson's proposals will only work if teachers are given a much bigger role in the marking of AS. His plan to split AS from A2 will simplify sixth-form exams and cut the number of complicated statistical adjustments needed to work out the final grade. But it will also mean that schools are free to abandon AS and enter pupils simply for A2.
Secondary heads are confident that most schools will remain faithful to their belief in broadening sixth-form education and continue to offer AS. But some may decide to drop an exam that is accused of decimating extra-curricular activities and depriving pupils of a life outside work, particularly as university admissions tutors show little inclination to take it seriously. Schools will find AS an attractive option only if it involves much more teacher assessment and becomes more like internal lower-sixth exams, which pupils have to take anyway. Any reform must lighten the ludicrously heavy load of external exams.
As Mr Tomlinson recognises, ministers must proceed with caution. Charles Clarke was quick to deny that the proposal would lead to a complete overhaul of the system. After this summer's buffeting, the last thing sixth-form teachers need is a fresh upheaval. The problems arose because the new A-level was introduced too quickly before it had been piloted.
Teachers would welcome an end to the confusion over how the two parts of A-level fit together, but they will want to be assured that AS and A2 can be uncoupled without changes to syllabuses and yet another set of instructions about the standard expected at A-level. Otherwise, Mr Clarke, forget it.