A Southampton head teacher has written to the Education Secretary to highlight the plight of teenagers she believes were cheated out of English GCSE grades.

Ruth Evans, head at Cantell Maths and Computing College, wants to see the Government force action over the fiasco caused by unannounced changes to the marking scheme halfway through the key course.

As reported, the shift in grade boundaries imposed without warning by exam boards meant some pupils failed, despite getting better scores than others who passed earlier.

Across Southampton, more than 130 missed out on vital C grades. Leaked letters have revealed officials from exams watchdog Ofqual pressurised awarding bodies to put a halt to rising English grades.

An alliance of schools, unions, councils and professional groups has been set up to fight for a change in the grades, including representatives of several Southampton and Hampshire secondaries, which is currently considering legal action. But so far, neither Ofqual nor the two main exam boards, Edexcel and AQA, has admitted any responsibility or wrongdoing.

A petition has been lodged with the Government calling for an inquiry into the affair, which several schools in the Daily Echo region have already urged parents to sign.

Southampton Test MP Alan Whitehead has already visited Cantell to discuss the situation with Ms Evans, as well as Graham Wilson, head at St George Catholic School and chair of the Southampton Secondary Heads Forum.

The Cantell head has also discussed the scandal with Southampton’s other MPs, John Denham, who will be visiting the school in the coming weeks, and Caroline Nokes, who has herself been in contact with Ofqual to complain about the debacle.

In an impassioned letter to Secretary of State for Education Michael Gove, Ms Evans said 19 Cantell pupils “who worked hard and with tremendous dedication”

had been given D grades instead of the Cs they were expecting and deserved.

She told the Tory MP staff have been “powerless to prevent them feeling they have failed”

Ms Evans wrote: “This has affected what they next do at college with all of them facing, at the very least, a retake in English next year.

“The local colleges have been supportive but a number of students have had to change college and courses, as a consequence.”

“As a school, this has meant that our overall headline figure for 5 A*-C is 53 per cent rather than 58 per cent.

“Our challenging school target was 50 per cent, so we have done well, but the headline we can publish does not accurately represent the tremendous progress we have made as a school.”