This year's A Level results show more students than ever achieving top marks.

The annual row over the exam's standards is expected as figures show an increase in the pass rate from 94.3 to 95.4 per cent.

The number of A grades awarded also rose by 0.9 per cent to just over a fifth of candidates.

This is the second year under a new system, in which students first choose five subjects to study at AS Level, reducing to three subjects for the A Level a year later.

Last year the A2 exams - those taken by 18-year olds - were marred by controversy when it was revealed a number of papers had been marked down.

Nearly 2000 students had their grades changed after remarking and a review by former schools chief inspector Mike Tomlinson.

But the government has focused on the latest round of results.

"Today is an important day for many pupils and they should be proud of their efforts. Their achievements are a tribute to their hard work and that of their teachers," said schools minister David Miliband.

"Our responsibility is to ensure that every pupil gets grades which reflect the standard of their work.

"I am encouraged by reports by the Qualifications and Curriculum Authority, by representatives in the public and private sectors and from Mike Tomlinson that the grading process this year has been fair to all concerned.

"I thank them all for their hard work to overcome the problems of last year."

The results were welcomed by the NASUWT union.

"I congratulate warmly all the students and their teachers on their hard work and commitment which is reflected in today's results," said general secretary Eamonn O'Kane.

"They should treat with contempt those who year in, year out repeat their parrot cry that standards have fallen.

"A Levels remain a testing experience for all students and their achievements in gaining these results should be applauded not denigrated."

However, the Liberal Democrats called for reform of the examinations system.

"For too long, exams, not the best interests of students, have run our education system," said education spokesman Phil Willis.

"I want to see any reforms making education relevant to the next step students want to take. A society with mass education participation cannot continue with a system that condemns 50 per cent of students to the scrap heap at 16, and concentrates exclusively on exams as a measure of its success.

"Clearly tuition fees are a major disincentive to those who want to go on to university. The prospect of five-figure debts already means that nearly 5,500 school leavers who could be expected to go to university will not do so. The government must abolish tuition fees to ensure equal access."