The grades will help students decide their next step, be it to stay in school to take A-levels, or a vocational qualification, or to leave education for the world of work.

Experts are predicting a bumper crop of results, with a possible one in five achieving A* or A grades.

The proportion of students attaining five good GCSEs (grades A* to C) is also expected to rise, topping last year when 63.3% of exams were awarded this standard.

Professor Alan Smithers from the University of Buckingham said: "It is pretty safe to assume that the pass rate at A* and A is going to be 20% of more this year."

Professor Smithers said he also expected to see maths results rise this year.

"There has been a lot of effort put into improving maths standards.

"We could be starting to see some of the fruits of that.

"The structure of the exams has also been changed to allow more students to have a crack at getting a C grade."

Previous years have seen different levels of maths exams set, which meant some pupils sitting a lower paper could not get a C, Professor Smithers said. This has not happened this year.