The education minister Nick Gibb has admitted he was warned about concerns that the algorithm used to determine exam grades could disproportionately affect poorer pupils. In a round of media interviews on the morning GCSE results were published, the minister defended the standardisation system, insisting the model was fair but that it was implemented incorrectly. He apologised to pupils for the chaos that ensued although was unable to give a firm date for the release of Btec results, which have been delayed, saying they would “hopefully” be out next week. Asked about reports that ministers were warned weeks ago of flaws in the exams algorithm that left thousands of A-level students devastated and university admissions in disarray, he conceded he had been aware of the issue and a meeting had taken place. The Times reported that Sir Jon Coles, a former director general at the Department for Education (DfE), wrote to the education secretary, Gavin Williamson, early last month to express concerns about the algorithm used by the exams regulator Ofqual. Speaking to BBC Radio 4’s Today programme, Gibb said: “He [Coles] spoke to me about it and he was concerned about the model and he was concerned that it would disadvantage particularly children from poorer backgrounds. And so I called a meeting therefore with the independent regulator, with Ofqual, to discuss in detail those very concerns.” Gibb said it “certainly was foreseen” that private school pupils could benefit from the use of the algorithm, because it was already clear that small cohorts had to rely more on the teacher-assessed grade than on the standardisation process, but he said that applied to the state sector as much as to the independent sector. “What was always at the forefront of my mind was that no young person from a disadvantaged background would see their grades standardised to a greater extent than other young people,” he said. “There was about a 2% difference, that’s broadly what we saw in the national results last week, in contrast to what we saw in Scotland where there was a big gap between disadvantaged pupils. And that’s because in this country we had more data about the prior attainment of young people that was built into the model. “So the model itself was fair, it was very popular, it was widely consulted upon. The problem arose in the way in which the three phases of the application of that model – the historic data of the school, the prior attainment of the cohort of pupils at the school, and then the national standard correction – it’s that element of the application of the model that I think there is a concern.” The minister went on: “The application of the model is a regulatory approach and it’s the development of that that emerged on the Thursday when the algorithm was published. And at that stage it became clear that there were some results that were being published on Thursday and Friday that were just not right and they were not what the model had intended. “It was not intended that a young person who had worked diligently for two years on their A-levels and was expecting an A and two Bs or three As, and turned up at school to collect their grades and they were three Ds.” Labour has called for transparency over the exams fiasco, saying the DfE must now publish all correspondence to and from Williamson in which concerns about the algorithm were discussed. The shadow education secretary, Kate Green, said Williamson was warned again and again about problems with the grading algorithm, and each time he did nothing. “This endless pattern of incompetence is no way to run a country. His failure to listen to warnings and to act on them risked thousands of young people being robbed of their futures,” she said. “It is time for full transparency. The Department for Education must now publish all correspondence to and from the secretary of state in which concerns about this algorithm were discussed, as a matter of urgency. Young people deserve to know how they came to be let down so badly.”