Maths teachers are calling for the introduction of a tough new GCSE to be delayed for a year, so they can properly prepare their pupils.

The reformed maths exam - dubbed the “big fat GCSE” because of its extra content - is supposed to be taught from September. But schools have not been given the sample material they need because exam boards have been told not to release any more until a row over standards has been resolved by Ofqual.

A decision by the regulator is not expected until the end of April at the earliest, prompting teachers to demand that the new GCSE be put back to give their students a fair chance.

TES has seen a letter from the Association of Teachers of Mathematics (ATM) suggesting it would be “prudent to delay the introduction of the new GCSEs by a year”.

In a letter to Ofqual’s chief regulator, Glenys Stacey, the ATM’s Sue Pope says the maths GCSE controversy has “seriously damaged” confidence in the watchdog.

“Many teachers are very concerned by what has happened with the recently accredited GCSE specifications, as usually they have a full year to prepare teaching for new specifications and want to choose their specification prior to embarking on teaching,” she warns. “Not least, because teachers like to share sample questions at appropriate times throughout their teaching as part of their preparation of students for the final, high-stakes examinations.”

The standards row erupted late last year over allegations that specimen papers from AQA were too easy - claims the exam board has denied. Ofqual is now conducting a large research project to investigate whether concerns over the AQA material, which it has already accredited, are justified.

But in a recent blog, Ms Stacey reveals that one of the project’s three “strands” has already been rethought because it was “unlikely to yield meaningful data”.

Ministers have made it known that they are “absolutely furious” that Ofqual has not done more to prevent what they fear could become a “race to the bottom” over standards in GCSE maths. But they are thought to be reluctant to see any further delays to the exam reform programme.

Now maths teachers are also voicing their displeasure at the regulator’s performance. Mel Muldowney, who teaches at Alcester Academy in Warwickshire, said more preparation time was needed before the new exam was introduced.

“This is about 550,000 kids who, potentially, could go into this unprepared,” she said. “We should have been able to look at a second set of assessment materials by now, but we don’t know what the finished result will look like from any exam board.”

But postponing the new maths GCSE would have significant implications. First teaching of a reformed maths A-level has already been put back twice, most recently to 2017 to ensure that anyone studying it will have sat the new GCSE. Any further delay would push the new A-level back for a third time to September 2018, three years later than originally planned.

Ofqual has already admitted that part of its original plan to look at the effectiveness of problem-solving questions - the issue at the heart of the concerns over the AQA material - will not work. But the regulator has stressed that although questions remain over the assessment materials, the curriculum and content that schools will have to teach will not alter.

Ian Stockford, Ofqual’s associate director of research and analysis, said: “We see no reason why the first teaching of GCSE maths would need to be delayed.

“Our research relates to exam board assessment methods, not the curriculum or its content. As such, the actual maths that will be taught in the classroom is not affected by our research programme or its findings.”