Government plans for a radical reform of A-levels have been dealt a further blow after experts warned they risk sparking a "collapse in the numbers" of pupils studying maths and the closure of university maths departments.
The Advisory Committee on Mathematics Education (ACME), which represents teachers and academics, has become the second high-profile body to write to Education Secretary Michael Gove to complain about the reforms.
Last week, The TES revealed that Cambridge University had rejected Mr Gove's proposals to scrap AS-levels from some versions of the exam and to put the emphasis on end-of-course exams (see clipping below).
In a letter to Mr Gove, Professor Dame Julia Higgins, ACME's chair, warns that making maths A-level harder "will mean fewer students choose to take the qualification".
She writes: "There is a real danger in making A-level mathematics significantly harder than it is currently. It would make it impossible to retain appropriate provision for the full range of students."
Previous changes to maths A-level in 2000 which made it more difficult led to a 19 per cent fall in the number of exam entries at the end of the two- year course in 2002.
The uptake took six years to recover after the Government made papers slightly easier in 2004 in a bid to compensate for the problem. Maths is now among the fastest growing of subjects.
"We feel it is very important that we warn you that implementing such a policy runs a genuine risk of repeating the collapse in the numbers studying A-level mathematics witnessed in 2002," Professor Higgins writes.
"We believe that it is very likely that we would again see university mathematics departments closing as a result of this fall in numbers."
Professor Higgins says it is "incorrect to assume that the modular system is for all subjects and all students."
She adds: "Modular courses make learning more accessible to more students, and almost all university courses are now modular.
"Consequently, it is entirely predictable that a compulsory move away from the present modular structure for mathematics and further mathematics A- levels would result in a substantial reduction in take-up."
Professor Higgins said ACME agreed that the brightest maths students must be "stretched and challenged" in their post-16 study.
But the best way to improve provision for high-ability teenagers in maths is to develop the papers that already cater for them, such as the Advanced Extension Award and STEP papers, used for Cambridge University admissions, the letter says.
It also warns that the proposed A* grade will have "no value in discriminating between the very best mathematics candidates".
Under the Government's proposals, exam boards would still be able to offer the ASA2 combination, but Mr Gove believes schools will abandon these exams if it is clear they do not meet university requirements.
Simon Gibbons, vice-chair of the National Association for the Teaching of English, said he could see advantages and disadvantages for his subject in Mr Gove's plan, depending on the type of student.
But he added: "The whole discourse that A-level is too easy, and that we need a return to rigour, is rubbish."
Professor Higgins writes that while it is important to listen to of universities in designing A-levels, a range of institutions should be involved.
A spokesman for the Department for Education said: "It's clear that we need to restore confidence in public exams. We're listening carefully to universities, employers and academic subject bodies' views to ensure A- levels are rigorous and equip young people for higher education.
"We will look in detail at exam structure, including whether schools and colleges should be able to offer traditional two-year A-levels alongside or instead of modular A-levels. We will set out detailed next steps later this year."