MPs have called for fundamental reforms of the school exam system to halt what they call a decline in standards.
A report from the all-party Education Select Committee said the quality of GCSE and A-levels had been adversely affected by a system which allows competition between exam boards.
It says boards should be stripped of their right to decide the content of examinations.
Instead the MPs favour the introduction of national syllabuses. They hope this will prevent boards from lowering the quality of exams in the fight for more market share.
The new national syllabuses would be accredited by Ofqual, the qualifications regulator.
The committee chairman, Graham Stuart MP, said: "The public have lost confidence in exam standards and this needs to be put right.
"We've got to stop the dumbing down of the courses young people sit and stop exam boards competing on how 'accessible' their syllabuses are.
"You could move to a single national exam board which would stop the 'race to the bottom' but the change would be disruptive and threaten innovation and cost control.
"Alternatively there are benefits to having one exam board per subject, but such 'franchising' would create its own difficulties with over pricing, tendering and the concentration of expertise. We believe the best reform would be the creation of National Syllabuses."
The committee wants to stop a system which allows schools to choose what they believe are the easiest exams, to boost their league table rankings.
The report comes after Government plans to scrap GCSEs and replace them with more difficult O-level style exams were leaked two weeks ago.
Teaching unions and education experts argued that this would lead to a two tier education system.
But the Education Secretary, Michael Gove, has since said he want to move towards a one-tier set of high quality qualifications.
The Lawrence Sheriff School in Rugby has topped the national GCSE performance table to three of the last four years.
The head teacher, Peter Kent, said: "If you talk to people in education, one of the biggest pleas they have got is for a period of continuity.
"All ideas are good and worthwhile, but the problem is when you move to one person's idea to another it causes a lot of instability in the system and it takes a long time to pick up and respond to it.
"We just want a period of stability so we can raise standards."
The committee's report suggests a pilot scheme to test its new recommendations.