The Association of Colleges, which represents further education and sixth form colleges, says that the introduction of a broader A level curriculum will mean more hours of study, which will particularly affect pupils who rely on part-time jobs for funding.

John Brennan, the Association of Colleges' director of further education development, is presenting a paper on the impact of the changes to the A level system at the association's summer conference in Cambridge on Wednesday.

Changes to A levels will mean more subjects and longer hours

The conference will hear that the extra pressure on time from A levels could push students into choosing to abandon their studies, rather than lose their jobs.

There will also be claims that broadening the A level curriculum will require extra staff, which smaller sixth forms will have difficulty in affording.

Dr Brennan will highlight the problems faced by the 55% of 16-year-olds who are currently studying for exams and working part time. An expansion of the hours needed for A level studies will mean that "children from poorer backgrounds will have to take some hard decisions".

"Young people from better-off families will benefit from the new curriculum," said Dr Brennan, while the most disadvantaged students "are the most likely to drop out".

The changes to the A level curriculum will mean students taking up to five subjects in the first year - which will be called advanced subsidiary or AS levels - before specialising for three full A levels in the second year.

Curriculum widened

There will also be a greater emphasis on coursework rather than exams, which again could increase the number of study hours across the two years of the syllabus.

The government has sought to encourage a widening of the curriculum for 16-year-olds, without threatening the 'gold standard' of the traditional A level.

Dr Brennan says that the government needs to provide an educational maintenance grant for all post-16 students, a policy that the government is examining with a number of pilot studies.