A-level pass rates reached a new record level this year

Under the current rules, candidates can only sit each unit of a course twice before "cashing in" the marks towards their final grade.

The Qualifications and Curriculum Authority (QCA), which regulates exams in England, said the change would remove complicated rules brought in in 2000 which affected very few students.

The move comes after a record percentage of A-level passes this summer.

'Practical reality'

A QCA spokesman said: "It will have a minimal effect on the number of students who take re-sits.

"Statistics show that very few students sit the same unit repeatedly."

Prior to the introduction of Curriculum 2000 three years ago, students were allowed to re-sit exams as many times as they liked.

Dr John Guy, principal of Farnborough Sixth Form College said: "This is a welcome reduction in bureaucracy, which mirrors the practical reality of the use of re-sit opportunities by students in recent years.

"The vast majority of students do not take re-sits anyway and those that do really only have time to take one in the course of a two-year programme.

"The removal of the rule will particularly help students who were ill or otherwise disadvantaged at the time of an exam, and especially those who want to extend their studies into a third year."

The QCA's change of policy comes after the A-level pass rate reached 95.4% this summer, up from 94.3%.

More than a fifth of entries were awarded the top A grades, leading for calls to create an A* grade to differentiate between the brightest students.

Andrew Grant, Headmaster at the independent St Albans School, Hertfordshire, said: "What this relaxation will do is to reduce a layer of bureaucratic complexity that has bedevilled the work of examination officers and confused candidates for no good practical reason."

A Department for Education and Skills spokesman said: "Currently less than 1% of pupils re-sit their A-levels.

"This is not a question of making passing any easier. This is simply a mechanism to reduce bureaucracy and simplify an overly complex system.