Exams regulator Ofqual has been slammed by a Tower Hamlets head teacher following the fiasco over this year’s GCSE English grades.

Kenny Frederick, head of George Green’s School on the Isle of Dogs, has written an open letter to Ofqual accusing it of incompetence after thousands of pupils were left with D grades instead of the C grades they expected in English exams.

The controversy began after Ofqual changed the grade boundaries before pupils sat the exam. The changes left many teachers and pupils furious at the regulator, which cites “over-marking” as the cause of the problems.

“George Green’s School has no confidence in the work that Ofqual is doing”, writes Ms Frederick.

“In my opinion Ofqual is poorly led and seems unwilling and unable to accept responsibility for its own mistakes. To put the blame on teachers is intolerable.”

Ms Frederick is now calling on Ofqual to publish exam board reports to back up claims that marking is to blame for the problems facing pupils.

“Good leaders take responsibility for their own mistakes and do not use others as scapegoats”, she added.

George Green’s had 19 pupils who missed out on their projected C grades, despite consistent improvements in exam results in recent years.

It has now joined forces with other schools and local authorities – including Tower Hamlets – to challenge Ofqual to re-grade affected papers.

However, the regulator stands by the findings in its report. A spokesperson said: “Our report recognises the pressures that schools and teachers are under.

“Nowhere does the report say, and nor would we want to suggest, that all schools were over-marking.

“But the over-marking was significant enough to make awarding difficult, and to contribute to the unexpected results we saw.”