Teenagers will be able to use their grades in mock GCSE and A-level exams to apply to university and for jobs, the Government is to announce.
They are expected to say the grades will carry the same weight as the moderated results to be awarded in the coming days.
Ministers had been under pressure over A-level grades in England after 124,000 students in Scotland had their exam results upgraded due to a botched system.
Unions had called on the Government to follow Scotland's lead in scrapping the grades which had been moderated so that this year's results were not significantly higher than previous years.
Labour leader Keir Starmer had warned that Boris Johnson risked “robbing a generation of their future” unless he urgently fixed the unfair exam grading system.
He added: “Parents are worried that years of hard work are about to be undone because a computer has decided to mark their child down.”
But now Education Secretary Gavin Williamson is due to tell students awaiting their A-level results on Thursday they can keep their grades in mock exams if they are higher than the moderated one.
Students will still be able to sit exams in the autumn if they are unhappy with the grades they secured in mock exams, or if they are dissatisfied with results awarded by exam boards on Thursday.
All three grades will hold the same value with universities, colleges and employers, the Department for Education is expected to say.
But the appeals process - where individual students in England are dependent on schools and colleges to appeal against results on their behalf - is expected to remain the same.
Mr Williamson said: "Every young person waiting for their results wants to know they have been treated fairly.
"By ensuring students have the safety net of their mock results, as well as the chance of sitting autumn exams, we are creating a triple lock process to ensure they can have the confidence to take the next step forward in work or education."
