PRIVATE schools have called on the Government to look again at introducing an A* grade at A-level, amid claims that universities and employers can no longer to identify the best students.

Writing for The TES, Geoff Lucas, secretary of the Headmasters’ and Headmistresses’ Conference, warns of potential “anarchy” in the exam system if ministers fail to address the issue.

The warning comes after this month’s results showed the proportion of A grades climbing to a new high of 21.6 per cent. Mr Lucas said the figure in the private sector was 40 per cent, with many schools boasting nine out of 10 of their entries were awarded an A or B. Nationally, 7.5 per cent of students got three or more A grades last year.

Downing Street was keen on the idea of an A* grade last year. But ministers have gone cold on that plan, after opposition from state headteachers. A separate proposal for a new “distinction” A-level, with more challenging questions for the most able, was also sidelined after heads’ protests.

Instead, the Government now favours Advanced Extension Awards: more difficult exams that bright students can opt to take.

However, only 7,230 students took the AEA this year and public schools dislike it. “No one...really believes that AEAs are the answer,” said Mr Lucas. “These costly, demotivating, exclusive and time-consuming exams are unsustainable in the long-term.”

Until now, the 243-school HMC, which is influential with the Government, has been against the idea of an A*. But Mr Lucas said it should be reconsidered because A-levels were in danger of being “eroded” as universities introduced their own qualifications.

Oxford, Cambridge and London universities are introducing their own admissions tests for medical applicants this year. The Government’s universities admissions task force is also said to be considering recommending that prospective undergraduates sit American-style scholastic aptitude tests.

“If no solution to the problem of discrimination at the top is found (and soon), the A-level itself and any concept of national standards will be replaced by anarchy and incoherence as universities and employers go their own way,” said Mr Lucas.

The HMC’s shift to back the A* creates a divide with state schools, who still oppose it. John Dunford, general secretary of the Secondary Heads Association, said: “State school heads are completely against an A*, which would devalue the A grade and unbalance the grading system in order to solve a problem for a small number of university departments.”

Another way of discriminating between A-grade students would be to give out their exact marks. Exam boards and the Qualifications and Curriculum Authority are keen on this idea but The TES understands the Department for Education and Skills is sceptical.

The Government this week reacted to the news that GCSE pass rates had fallen to an 11-year low by pledging to raise the numbers staying in education beyond the age of 16. It said this would be a priority for a third Labour term.