Fresh concern over the grading of this year's GCSE exams emerged today as it was revealed grade boundaries in science had also been changed at the last moment.
In this case, the pass marks for A*, A, B and C grades in chemistry and biology at AQA (Assessment and Qualifications Alliance), the biggest exam board, were lowered between the January and June sitting.
Those who took it in the winter were awarded lower grades for the same marks as those taking it in June and less than one per cent of biology candidates achieved an A* grade in January compared with more than 10 per cent in June.
In chemistry the respective figures were two and 12per cent.
However, an analysis of the results reveals the effects were mixed - with the lowering of the C grade in biology followed by fewer candidates achieving it.
AQA pointed out it was not the only board to change grade boundaries - similar changes occurred at the OCR (Oxford, Cambridge and Royal Society of Arts) exam board with some grade boundaries being raised and others lowered.
The revelations sparked off new claims for an independent inquiry into other exams system - first made when it emerged up to 65,000 GCSE English candidates may have been awarded a D grade rather than a C when grade boundaries were changed at the last moment.
"It is obvious that there are serious issues at the heart of the system," said Christine Blower, general secretary of the National Union of Teachers. "There urgently needs to be an independent inquiry into this matter now and for those examinations which have been affected by political tampering to be re-graded."
Meanwhile, the Church of England has written to Mr Gove, saying the GCSE English marking had caused "great distress to some of our most vulnerable pupils".
Those from disadvantaged communities expected to get a C grade pass were most likely to be affected.
The Bishop of Oxford, the Rt Revd John Pritchard, who chairs the C of E's Board of Education, said the "debacle" over the marking was "a considerable affront to natural justice".