A big reduction in the amount of time pupils spend taking exams is to be advocated by the Qualifications and Curriculum Authority, a government education watchdog.
Children will also be encouraged to take their GCSE exams a year earlier to avoid spending three consecutive years sitting external exams, because of the introduction of the AS-levels this summer.
Ministers and QCA officials are adamant there are no plans to abolish GCSEs. But headteachers' leaders argued yesterday that the only way to achieve a substantial cut in examination time would be to abolish the GCSE, the results of which are due to be received by more than 600,000 candidates on Thursday.
The shake-up, contained in a report to be published in December, is likely to lead to a decline of the GCSE exam as an end-of-education external test. Independent schools have already reduced the number of subjects taught.
The reduction in exam time was forecast yesterday by Professor David Hargreaves, chief executive of the QCA, who said: "The time spent in examinations in future will be significantly less than it is today. A lot of people are arguing that we haven't got the balance right between assessment and teaching. I have a lot of sympathy with that view. You can't go on giving people endless exams. What we need is high-quality exams, not high quantity. I don't think it follows that the longer you make a student spend in an exam room, the more rigorous the assessment."
David Hart, general secretary of the National Association of Head Teachers, said: "Unless you do something drastic, you can't get away from the fact that we have three external examinations in three years. The only way you can significantly reduce the number of examinations is to abolish the GCSE. But you can only do that when you have achieved complete confidence in the quality of education at key stage three [the curriculum for those aged 11 to 14]."
Mr Hart predicted the GCSE would not be abolished for at least five years.
Heads want to see a more rigorous national curriculum followed by a baccalaureate-style, wider syllabus for those aged 14 to 19. Ministers, concerned that the standards of many students in the "three Rs" drop during first year at secondary school, are giving priority to introducing a more rigorous approach to teaching standards in the 11 to 14 age group. Initiatives include extending the literacy and numeracy hours from primary schools to secondaries.
Mr Hart said: "You have to have some record for those who leave school at 16. A record of achievement to replace the GCSE could be the right way forward."
The reduction in exam time will be overwhelmingly welcomed throughout the education system. The plethora of exams taken this summer is what headteachers say has increased pressure on the exam boards.
The future for education from 14 to 19 will be spelt out in a review to be published by the QCA this December. This is the second stage of a review of AS-levels, which will pave the way for a reduction in the number of tests sat by sixth-formers next year.Reuse content