Several high-performing state schools, including the London Oratory, where the Prime Minister sent his children, are keen to let students take the exams, which often contain no coursework and are seen as more rigorous.
However, they cannot receive funding for the courses because they are not on the section 96 list of exams approved by the Qualifications and Curriculum Authority.
More than 200 independent schools in the UK, including Winchester, Rugby, Harrow and Cheltenham college, have already switched to the maths iGCSE, which covers challenging subjects such as calculus in greater depth.
They are eager for the exams to be approved by the QCA because their pupils' results are not included in league tables, although the exams are welcomed by universities and the Universities and Colleges Admissions Service.
A delegation of teachers, organised by the Headmasters' and Headmistresses'
Conference and the Girls' Schools Association, met officials from the QCA to press their case.
Geoff Lucas, HMC secretary, said that the meeting had been encouraging and that the group now hoped to persuade the boards Edexcel and OCR, which both offer the exams, to apply to the QCA for recognition.
He said one sticking point would be convincing the QCA that schools would not confuse the iGCSE with the national exam.
The delegation included teachers from Rugby, Norwich school and Winchester college which has used the iGCSE for seven years and is considering switching to the international A-level for English.
Tim Wilbur, principal of Rossal school in Lancashire, said that the school had received a lower rating in league tables than it deserved last year because 50 of its 120 pupils had only sat iGCSEs.
Jim Hawkins, head of Norwich school, used an end-of-term speech to explain to parents why it had switched to the maths iGCSE. "There is no coursework, no mind-numbing statistical number-crunching that wastes up to four weeks'
teaching time," he said. "It is absurd that only independent schools are able to opt for this sort of course."
Roger Dancy, chief master of the private King Edward's school in Birmingham, wrote in the parliamentary magazine The House this week that it was absurd the iGCSE was not recognised by league tables when ABC certificates in cake decoration were.
A QCA spokeswoman said that the authority would have to be approached by one of the exam boards before it could begin considering including iGCSEs on the section 96 list and that it could be a lengthy process.