A-level maths is to be made easier amid fears that the falling number of sixth formers choosing the subject could see it disappear from universities.

The new regulations will allow sixth formers to get an A-level by studying four "more manageable" AS-level modules plus two units at the more demanding A2 standard. At present all students must take three AS units followed by three at A2 level to qualify for an A-level in any subject.

Damian Green, the Conservative education spokesman, condemned the revamp of maths by the Qualifications and Curriculum Authority as a blatant attempt to "dumb down" the exam to attract more students into the subject.

Ken Boston, the QCA's chief executive, denied that the new arrangements would make the exams easier. He said urgent change had become necessary after the number of students taking maths slumped by 20 per cent in two years.

The review of the maths syllabus followed disastrous results in AS-level maths in 2001, the first year of the exam, which saw a third of candidates fail. A government investigation concluded that the exam had been too hard and ordered new tests to be developed for introduction in 2005. The number of A-level maths entries fell to 53,940 last summer, compared with 66,247 in 2001.

The new A-level, to be taught from September next year, will have a narrower syllabus and will put greater emphasis on pure maths. Pure maths will account for two-thirds of the new course, rather than the half as now, and will repeat some of the pure maths from the GCSE. The new exam will offer fewer options in applied maths.

The QCA said all students would still have to cover the same "core" content and the "intellectual rigour" of A-level maths would be maintained.

The Mathematical Association and teachers backed the reforms, describing them as a "pragmatic" response to the unpopularity of the subject in sixth forms.

But Mr Green said the reforms were an obvious attempt to make the exam easier. "It looks alarmingly like dumbing down to make sure that the results don't get any worse," he said. "Universities will have problems if they get A-level students arriving at university without having covered the necessary mathematical material at school."

Dr Boston said the reform was necessary to halt the decline in the subject's popularity. "We believe that maths is vital to the national interest, and it is worrying that there could soon be a generation of young adults who are missing out on maths beyond GCSE," he said. "These changes do not mean that maths is easier. The high standards that we have always expected of A level students will continue."

Peter Thomas, of the Mathematical Association, praised the QCA's "pragmatic response" to a difficult problem. "The new criteria will make GCE [A-level] mathematics more accessible while ensuring that students will have a deeper understanding of the material covered," he said.

The disciplines

In

Algebra; geometry; trigonometry; differential equations; quadratic equations

Out

Advanced statistics: normal distribution; continuous random variables

Mechanics: centre of mass; motion in a circle; coefficient of restitution; energy, work and power