Teenagers at hundreds of secondary schools are being entered for two English qualifications to boost results.
As well as taking GCSE English, these pupils are also taking an International GCSE (IGCSE) in the subject as schools attempt to achieve better grades and secure a higher ranking in league tables, the Times Educational Supplement (TES) reported.
Around 320 secondaries are believed to be entering at least some of their students for both courses, a strategy which is being promoted by the Performance in Excellence Club (PiXL).
The not-for-profit club, run by former headteacher Sir John Rowling, offers schools a number of ways to help improve GCSE results. An estimated 400 secondaries across England are part of the club and, of these, about 80% are thought to have at least some pupils taking GCSE and IGCSE English, the TES reported.
Sir John said the main purpose of the plan is to help more students achieve a decent English grade, but he acknowledged it was also a "belt and braces" approach for schools.
"Most heads thought the IGCSE was just for independent schools and that it didn't count towards league tables, but we have studied it very carefully and we've found it can be very appropriate for some state school students," he told the TES.
The Government announced two years ago that state schools in England would be able to offer IGCSEs, and that the qualifications would count towards league tables.
The exams have long been favoured by many private schools, which argue that they are tougher than GCSEs. They are considered more traditional, with pupils taking exams at the end of the two-year course rather than in bitesize chunks.
Sir John told the TES that more schools have become interested in the strategy following this summer's GCSE English controversy. Headteachers say thousands of teenagers received lower than expected grades in the subject this year after the grade boundaries were moved between January and June.
Sir John told the TES: "Teachers work like slaves all year then, at the end of it, get messed about. They invest all that effort just to be scuppered at the last minute, so I say if there is another alternative then use it."