Tens of thousands of A-level students in England are set to see their grades increased after a humiliating U-turn by the Government.
Following criticism from students, headteachers and a backlash by Tory MPs, grades will now be based on teachers' assessments rather than the controversial algorithm devised by regulator Ofqual.
Prime Minister Boris Johnson and Education Secretary Gavin Williamson had previously defended the "robust" system, which saw almost 40% of grades reduced from teachers' predictions.
Mr Williamson apologised for the distress caused by the handling of the process, which followed the cancellation of exams due to coronavirus.
Mr Johnson, who is on holiday in Scotland, held crisis talks with Mr Williamson and senior officials on Monday morning.
The change will also apply to GCSE results in England, which are due to be released on Thursday.
Students who were awarded a higher grade by the moderation process will be allowed to keep it, but for many pupils, their teachers' predictions could see their grades increased.
Mr Williamson said: "This has been an extraordinarily difficult year for young people who were unable to take their exams.
"We worked with Ofqual to construct the fairest possible model, but it is clear that the process of allocating grades has resulted in more significant inconsistencies than can be resolved through an appeals process.
"We now believe it is better to offer young people and parents certainty by moving to teacher assessed grades for both A and AS level and GCSE results.
"I am sorry for the distress this has caused young people and their parents but hope this announcement will now provide the certainty and reassurance they deserve."
Labour leader Sir Keir Starmer said: "The Government has had months to sort out exams and has now been forced into a screeching U-turn after days of confusion.
"This is a victory for the thousands of young people who have powerfully made their voices heard this past week."
Ofqual chairman Roger Taylor apologised for the "uncertainty and anxiety" caused by the fiasco.
"Our goal has always been to protect the trust that the public rightly has in educational qualifications," he said.
"But we recognise that while the approach we adopted attempted to achieve these goals, we also appreciate that it has also caused real anguish and damaged public confidence.
"Expecting schools to submit appeals where grades were incorrect placed a burden on teachers when they need to be preparing for the new term and has created uncertainty and anxiety for students. For all of that, we are extremely sorry."
The devolved administrations in Wales and Northern Ireland also announced they were moving to teacher-assessed grades.
The Scottish Government was forced into a U-turn last week after a backlash about the moderation system used there, giving advance notice of the chaos elsewhere in the UK.
But UK Government ministers had previously insisted they would not follow the example set in Holyrood.
Mr Williamson had claimed there would be "no U-turn, no change" and a shift like Scotland would lead to "rampant grade inflation".
Last week Mr Johnson said the system was "robust" and "dependable".