EXAM regulator Ofqual has refused to remark GCSE grades this summer, despite mounting pressure from teachers and their unions.
A number of Mid Devon students claimed to be left with lower marks than expected after boards controversially altered benchmarks.
They were changed in such a way that many pupils who would have achieved a C grade in January would have scored a D for exactly the same work six months later, claims Andy Woolley, the South West's Regional Secretary for the National Union of Teachers.
Head teachers across the district expressed their intention to launch appeals on behalf of their pupils including Andrew Lovett, from Tiverton High School, where grades in English were two per cent down on those achieved last year.
Queen Elizabeth's Academy in Crediton is among 28 Devon schools to sign a letter of protest over the changes.
The letter reads: "We believe this move by a number of exam boards to move the mark boundaries artificially by the end of the year to be perverse, unfair and to make a complete farce of the marking and assessment process."
Michael Johnson, executive head teacher of the Chulmleigh Academy Trust, said he was left "bemused" by results.
"Our students have achieved grades below those we would have predicted in previous years," he said.
"This has had a serious impact upon many individual results. While we are in favour of putting more rigour into the system, it cannot be right that many schools see such a big decline in English grades.
"Our students are as bright as the year before, our English teachers are the same and have managed to get outstanding grades consistently for the last few years.
"I hope the further education colleges will take this situation into account when admitting our students. A sudden policy shift should never adversely affect the chances of our students."
Many other schools in Devon saw dramatic declines in results for English this year, in some cases up to 10 per cent.
Mr Woolley said: "The only way of putting right the injustice faced by students, teachers and schools is that this summer's exams should be re-graded, not re-marked using the same criteria applied in assessing the work of January's entrants."
Teaching unions are angered that many pupils now face the prospect of re-sitting exams rather than having their papers automatically re-graded.
After carrying out a review into the issues first raised last week, Ofqual chief executive Glenys Stacey said on Friday that it had found that the June boundaries had been properly set and the problem rested with the January standards.
However she said the papers had been fairly marked, and pupils could re-sit the exams early.
Ms Stacey said examiners had used their best judgement in setting grade boundaries at all times, but those marking in January – when just seven per cent of candidates had sat the unit causing concern – had had less data and information to work with.