A political spat has broken out after the Education Secretary accused his Welsh counterpart of being irresponsible in ordering a re-grading of GCSE English results in Wales.
Michael Gove launched a scathing attack on Welsh education minister Leighton Andrews, insisting that he is damaging children's education and attempting to shift the blame.
Mr Andrews, a Labour politician, hit back, arguing that Mr Gove has "undermined parental confidence in GCSEs".
The row came as England's exams regulator, Ofqual, announced that it has written to the Welsh Government about Mr Andrews' decision to order the WJEC board, which sets GCSE exams in both England and Wales, to re-grade English language GCSE results in the principality.
Ofqual argued that the results should not be re-graded and asked for an urgent meeting.
Mr Andrews's decision is at odds with Ofqual which insists it would be inappropriate for exams to be re-graded. Its inquiry into the fiasco concluded that January's GCSE English assessments were "graded generously" but that the June boundaries were properly set and candidates' work properly graded.
WJEC has called for regulators on both sides of the border to come to a common view on how to proceed.
Giving evidence to the Commons Education Select Committee, Mr Gove ruled out ordering an independent inquiry into the grading fiasco. He said it is right to have an independent regulator, accountable to Parliament, to take decisions.
"I think it would be quite wrong for me to appoint over that regulator an outside body in order to second-guess those decisions," he said.
It has been estimated that thousands of teenagers received lower-than-expected English results this year after the grade boundaries were moved between January and June.