Video report by ITV News Political Correspondent Daniel Hewitt
Ministers were warned about the risk to disadvantaged pupils of using a standardisation model to calculate A-level results weeks ago, ITV News has been told.
Robert Halfon, the chair of the Commons Education Select Committee, said they warned ministers and exams regulator Ofqual as early as June that the model "may impact on disadvantaged pupils".
"We urged them to publish the model weeks in advance so that it could be scrutinised properly by those in the know," he said.
Earlier, Schools Minister Nick Gibb admitted he did not see the controversial algorithm which downgraded at least 40% of A-level results, until the exam results were published last Thursday.
Hundreds of thousands of grades were downgraded from what teachers had predicted for students by a standardisation formula which assigned grades to students partially based on their previous attainment and on grades achieved by previous years at their school or college.
Pupils from disadvantaged backgrounds were said to have been worst hit by the standardisation process.
A u-turn was eventually performed allowing students to use their predicted grades and Education Secretary Gavin Williamson apologised for the fiasco, but many believe it could have all been avoided if the government had scrutinised the algorithm being used to standardise grades.
Mr Halfon said the committee published a report in early July saying it had "problems" with the model and "urged Ofqual to publish it, this so called algorithm, so that it could be picked apart and scrutinised".
"That wasn't done," he said, adding: "We need to find out what on earth has gone on between Ofqual and the Department for Education."
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When asked why he did not ask to see the algorithm before exam results were published, Mr Gibb told ITV News "the issue for us was the model, the algorithm is the implementation of the model by the independent regulator".
"The independent regulator developed the model, they consulted on it, it had wide support, it was a fair system, the model," he said.
"Something went wrong, however, in the way the model translated intro grades using the algorithm."
Mr Halfon said his committee also warned about issues with the A-levels appeals process, which he said was "too narrow".
"If you were a child of a Supreme Court judge you might just know how to navigate it," he said.
On Wednesday, Labour claimed the algorithm used to calculate the grades was unlawful.
Shadow attorney general Lord Falconer argued that both ministers and the exams regulator would have been aware that the algorithm was in breach of the law at least three times.
Lord Falconer said the standardisation formula used to calculate grades was in breach of the objectives under which Ofqual was established in 2009.
In a joint letter with shadow education secretary Kate Green, addressed to Education Secretary Gavin Williamson and chief regulator of Ofqual Sally Collier, Lord Falconer said the algorithm "does not accurately reflect that student’s level of knowledge skill and understanding".
“This is clearly not in compliance with objective one, and therefore cannot allow for a proper comparison with other boards or years, because there is no proper assessment of this years’ students.”
According to the law which established Ofqual - the Apprenticeships, Skills, Children and Learning Act 2009 - the regulator must "secure that regulated qualifications give a reliable indication of knowledge, skills and understanding".
Mr Gibb said an independent inquiry will be carried out to examine what happened during this process.