Exam Standards have fallen, according to the former head of the UK's biggest exam board, who this week revealed that he resigned after being expected to manipulate GCSE results by Ofqual.
"Top grades no longer automatically mean top students," Jerry Jarvis, who ran Edexcel between 2005 and 2009, writes in a new book. "Have standards fallen? Yes, I think they probably have."
It also explains that the reason behind his shock departure from the board in September 2009 was that Ofqual, the exams watchdog, wanted him to "artificially" adjust marks downwards in a bid to prevent modular GCSEs - still being used - causing grade inflation.
"I could not accept this further manipulation of an already complex assessment process," he writes. "I would no longer be able to claim publicly that the grades awarded reflected the ability of the students that I was responsible for assessing."
His comments come days after education secretary Michael Gove gave notice that decades of ever-improving results are to end, with tougher exams meaning fewer passes.
In a TES interview, Mr Jarvis said he lost confidence in Ofqual. "I was issued with guidance to deal with the problems of adding the results of different modules together," he writes. "This meant that I had to award the grades that every student deserved for each module, but then had to apply adjustments to avoid inflation in the overall grade."
A similar situation with new modular A levels prompted the 2002 grading scandal that saw the sacking of the head of an exams watchdog and led in part to the resignation of education secretary Estelle Morris.
Mr Jarvis was the only casualty of the 2009 GCSE changes, which left him in a quandary. "If I were to follow the rules and grade each module as it should have been then I was liable to have grade inflation," he told TES. "So what I was being required to do really was to anticipate the grade inflation and mark a bit harder."
Colleagues on other boards and inside Edexcel had told him: "Whatever we do, we have to find a way to make the standards the same as last year."
"I found that increasingly difficult," he said. "Ultimately, I took my problem directly to the chair and chief executive of Ofqual and said, 'Take it or leave it, I don't want to participate in this process.'"
Mr Jarvis felt unable to make his concerns public then because of a danger that they would be taken out of context. He has chosen to speak out now, he said, because modular GCSEs are to be abolished. In fact, although all exam modules will be sat at the end of courses from 2014, the structure that prompted some of Mr Jarvis' concerns will remain.
This week, Glenys Stacey, Ofqual chief executive since 2010, said: "We know that policymakers, experts and others have different views about how qualification grades should be managed, but one thing is clear - they do need to be managed so that the outcomes, as between one awarding body and another, are fair and that they are comparable year on year."
She said Ofqual was determined to tackle grade inflation and last summer's first modular GCSEs results saw the number of top grades remain "in keeping with the previous year".
Mr Jarvis writes that exam standards have been maintained in the technical sense of measuring a specific level of performance. But he adds: "No amount of explanation by academics and experts can change the perception that something is wrong with so many students being awarded the top grades.
"No amount of technical data can convince us that standards have been maintained if the experience of employers is that many school leavers are not equipped with basic skills."
His book defends the right of boards to compete on the support they offer teachers. "Why shouldn't exam boards help students - and their teachers - to try to gain good grades?" he writes, repeating a position that some claim represents a conflict of interest.
Mr Jarvis told TES he was "shocked" by the recent revelations about the information given to teachers during exam board seminars, but that they were not an issue during his time at Edexcel.
The fallout from the seminar scandal continued last Friday when Ofqual revealed that it had asked boards to tighten geography, history, English literature and maths GCSEs to "make sure students cover the whole curriculum".
Cheats, Choices and Dumbing Down by Jerry Jarvis is out now, published by Pukka Publications.