Media playback is unsupported on your device Media caption Michael Gove: "Young people deserve an education system that can compete with the best in the world"

An overhaul of GCSEs in England has been announced by Education Secretary Michael Gove to help pupils in England "compete with the best in the world".

From 2015, GCSEs will move from coursework to exams at the end of two years and will be graded from 8 to 1, rather than A* to G.

"We need to reform our examination system to restore public confidence," Mr Gove told the House of Commons.

Labour's Stephen Twigg attacked "shallow" changes lacking in evidence.

Mr Twigg accused Mr Gove of "cutting back on re-sits, while affording himself a fourth attempt at GCSE reform".

Mary Bousted, leader of the ATL teachers' union, said the constant change in exams was turning pupils into "Mr Gove's guinea pigs".

'Merit'

Head teachers' leader Russell Hobby said the plans for a "more rigorous exam to the existing GCSE contain merit" but warned against an over-hasty implementation. "We need to take time to get any new assessment system right."

Wales and Northern Ireland are keeping GCSEs, but so far are not adopting the changes proposed for England.

Media playback is unsupported on your device Media caption Former schools minister Nick Gibb and NUT general secretary Christine Blower debate the changes

Ofqual head Glenys Stacey says: "We want to see qualifications that are more stretching for the most able students, using assessments that really test knowledge, understanding and skills."

There is no sign of a change in name to I-level for the English exams - as had been rumoured.

Key changes from autumn 2015

Changes will initially be for nine core GCSE subjects

Grading by numbers 8-1 rather than by the current letters A*-G

No more modular courses, instead full exams taken at the end of two years

Controlled assessments (coursework done under exam conditions) will be scrapped

Exams to be based on a more stretching, essay-based system

Pass mark to be pushed higher

The reforms will initially apply to a group of core subjects - English language and literature, maths, physics, chemistry, biology, combined science, history and geography.

'Whole book'

Hundreds of thousands of pupils will begin studying these revised GCSEs from autumn 2015 and the first candidates to take the exams will be in summer 2017.

Apart from exceptions such as practical experiments in science, there will be a shift towards results depending fully on exams taken at the end of two years. It will mean removing the 25% of marks in history, English literature and geography that are currently allowed for controlled assessments.

AROUND THE UK The GCSE changes being announced will only apply to pupils in England. Scotland has its own exam system, but Wales and Northern Ireland also use GCSEs. Wales is planning its own regulatory shake-up, but has already said it has no intention of changing from the GCSE brand. Wit no sign of a change in the name of the new exams in England, there are likely to be questions about how universities and employers will understand the different forms of GCSE.

Grading will be by numbers rather than letters - with 8 at the top and 1 at the bottom. The pass mark will be pushed higher, with claims it will compare with the highest-performing school systems, such as Finland and Shanghai.

But the National Union of Teachers said Finland used a high level of the type of student assessment being removed from exams in England.

The new GCSEs will push for a more stretching, essay-based exam system, reminiscent of O-levels, taken by pupils until the late 1980s.

Mr Gove told MPs that previous course specifications "were too vague" and had caused "suspicion and speculation that some exam boards were 'harder' than others".

History will require more study of British history. Pupils will have to write an in-depth study of a 25-to-50-year period within a range of eras stretching from 500AD to the present day.

There will be a less prominent world history section and pupils will be asked to study a theme such as changes in politics, religion or culture across the medieval, early modern and modern eras.

In English literature, exam questions will be designed to ensure that pupils have read the whole book.

The course content will include at least one play by Shakespeare, a selection of work by the Romantic poets, a 19th Century novel, a selection of poetry since 1850 and a 20th Century novel or drama.

For both English language and literature, digital texts are excluded.

Maths will promote the idea of developing independent problem-solving skills, rather than setting types of questions that can be rehearsed.

Education Minister Elizabeth Truss said: "We do need to start competing against those top performing countries in the world, because for too long we've pretended that students' results are getting better, when all that's been happening is the exams have been getting easier."

Brian Lightman, leader of the ASCL head teachers' union, said his greatest concern was about the proposed syllabus changes. "Simply making exams harder does not guarantee higher standards or mean that students will be prepared for a job. The curriculum should stretch and challenge the highest achieving students but it must also engage and motivate those who struggle at the other end."

'Rushed'

This is the latest stage in Mr Gove's drive to reconfigure the exam system.

Last year, Mr Gove announced plans for the scrapping of GCSEs and their replacement with English Baccalaureate Certificates, with each subject to be set by a single exam board.

This re-branding was scrapped, with GCSEs to be retained but reformed instead.

NUT general secretary Christine Blower said the the government's approach was "rushed".

"If you did this by consensus, by actually talking to the profession and understanding how best to examine things, we would be in a much better position."

Simply making exams harder does not guarantee higher standards or mean that students will be prepared for a job Brian Lightman, ASCL general secretary

Chris Keates, leader of the Nasuwt teachers' union, attacked the government's claim that the GCSE was a "broken qualification" and said it had "proved itself to be a robust and reliable qualification".

She accused the government of driving an "inaccurate and ideologically-driven media attack on the qualification".

The latest plans will be put out to consultation over the summer, with a timetable that will see exam boards producing courses to be accredited by Ofqual for teaching in autumn 2015.

The prospect of different forms of GCSEs in England, and Wales and Northern Ireland has raised the question of how they will be distinguished from each other.

The CBI said employers would want to be "crystal clear about the differences to eliminate any confusion".