GCSEs are to be scrapped and new, more rigorous O-levels brought back in the most radical overhaul of the school exams system for 30 years, it has been reported.

Education Secretary Michael Gove is set to abolish the national curriculum in English secondary schools according to leaked documents seen by The Daily Mail.

The new examinations will "meet or exceed the highest standards in the world for that age group", according to one document seen by the paper.

The plans are likely to set Mr Gove on a collision course with both the teaching unions and the Conservatives' Liberal Democrat partners in the coalition.

Under his proposals, pupils would begin studying for "explicitly harder" O-levels - covering traditional academic subjects such as English, maths, history, modern languages and the sciences - from September 2014. "Those starting GCSEs in 2013 are the last pupils who will have to do them," one document states.

Pupils will begin sitting the new O-levels from 2016, with papers set by a single examination board to provide a single "gold standard" test across the country. Less able pupils will sit simpler examinations similar to the old CSEs. They will include simpler tests in English and maths in order to provide them with "worthwhile" qualifications.

In order to encourage schools to adopt the new exam, the requirement that pupils should seek to obtain five good GCSEs graded A* to C will be abolished leaving them free to take the new O-levels.

Mr Gove is said to want to reverse a "historic mistake" by the Tories in the 1980s when he believes the creation of GCSEs led to a collapse in academic standards through grade inflation and a proliferation of "Mickey Mouse" courses.

The changes will see a return to individual examinations in physics, chemistry and biology instead of a single, combined science qualification. Maths students will be expected to study complex subjects such as calculus in order to get the top A grades, while English literature students will have to write longer essays and will not be allowed to take set texts into the exam room.

Mr Gove is said to be preparing to announce his plans formally in the next two weeks before launching a 12-week consultation. None of the changes require legislation.