Teenagers will not be allowed to take coursework projects home in many GCSE subjects under plans from the exams watchdog designed to stamp out cheating.
The proposals came amid fears that the growth in internet plagiarism and the desire of parents to "help" with their children's work were compromising the integrity of GCSEs.
The Qualifications and Curriculum Authority suggested that future specifications for the exams would see most coursework completed under controlled conditions in the classroom.
GCSE maths coursework could be axed entirely in favour of a qualification assessed 100 per cent by exam, according to QCA chief executive Ken Boston.
In a newly released letter to the then Education Secretary Ruth Kelly, Dr Boston said: "We recognise that the practice of students carrying out coursework at home and the wide availability of the inter-net have created greater opportunities for malpractice.
"This gives problems with ensuring authenticity - the extent to which we can be confident that internally assessed work is solely that of the candidate concerned.
"This is a threat to the fairness of GCSE."
He added: "We can improve authenticity and hence fairness by increasing the use of controlled conditions for coursework."
Ms Kelly had ordered the QCA to review the use of coursework in all GCSE subjects after the watchdog warned that cheating - particularly through the internet - was a growing problem.
Dr Boston's letter, dated April 7, represented the QCA's "interim" advice, which has been backed by regulators in Wales and Northern Ireland. Final recommendations will be made in the autumn.
Dr Boston suggested that future specifications for GCSE subjects should see a much greater emphasis on examinations and coursework tests completed under controlled conditions.
He said: "The consequence of these changes would be that in subjects that involve such activities as creating a physical product, carrying out investigations or performing with others, internal assessment is likely to continue but under conditions that maxim-ise fairness.
"Greater use of controlled conditions would also help reduce the assessment burden on students as they would normally take less time to complete their task under controlled conditions than otherwise."
But he warned that tightening the rules must not stop children acquiring the important skills that coursework projects can help develop.
"During its initial development, internal assessment in GCSE was seen as a way of enriching the curriculum and ensuring that all aspects of a subject that were important were taught and assessed.
"We want to ensure that a new approach to internal assessment, including increasing the use of controlled conditions, will not prevent students achieving important educational aims or developing valuable life and work skills."
But one subject likely to see coursework axed at GCSE is maths after the QCA's review suggested teachers had questioned its value. Dr Boston said the QCA was drawing up plans for the future of GCSE maths from 2007 to 2010.