GCSE maths results are behind those for subjects overall

Under the current three-tier entry system - decided by candidates' ability - the lowest-placed group can only get a D, however well it performs.

The Qualifications and Curriculum Authority proposes replacing this with two tiers, allowing all to gain a C.

Chief executive Ken Boston said it was vital to "inspire, encourage and motivate" maths students.

Large-scale trial

The revised assessment system, which brings maths into line with other GCSE subjects such as science and English, could be in place by 2006.

Several thousand pupils, due to take their final exams this summer, will be taking part in the QCA's pilot scheme.

Mr Boston said: "It is vital that we inspire, encourage and motivate young people in their studies by providing them with the opportunity to gain a grade C in GCSE mathematics.

"A two-tier model provides everyone with the opportunity, if they reach the required level, to gain a grade C."

In February, the government published its proposals for reforming education for 14 to 19-year-olds in England.

It said "functional" numeracy skills would have to be demonstrated before a candidate could achieve a C grade in GCSE maths.

Last summer, 51.7% of GCSE maths entries in England, Wales and Northern Ireland were graded A* to C.