Experts warn pupils whose marks are downgraded face missing out on university places while exam boards sift through appeals.
Universities have been urged by the UK Government to be flexible in their admissions ahead of A-level results day this week.
The eleventh hour move is in response to claims that the university places of thousands of pupils in England are in peril amid exam chaos.
Experts have warned that pupils whose marks are downgraded by computer face missing out on university places while exam boards sift through a flood of appeals.
Universities minister Michelle Donelan has written to vice-chancellors asking them, where possible, to hold places for students who appeal until they receive the outcome.
“Nobody should have to put their future on hold because of this virus,” she said.
“That is why I am urging universities to be as flexible as possible in their admissions and to hold places for those whose grades are being appealed.
“Our ambition for students this year is no different to any other year and it is in everybody’s interest to see them progress.”
The plea to universities follows an apology by Nicola Sturgeon to pupils in Scotland affected by the downgrading of exam results north of the border.
In a political embarrassment for the First Minister, pupils in the most deprived areas of Scotland had their exam pass rate downgraded by more than twice that of students from the wealthiest parts of the country.
And signalling an imminent U-turn, Ms Sturgeon said: “We will be taking steps to ensure that every young person gets a grade that recognises the work they have done.”
This year’s A-levels in England, Wales and Northern Ireland and Highers in Scotland were cancelled because of coronavirus, so marks have been based on teachers’ estimates of what pupils would have achieved.
In England, exam boards are expected to lower nearly 40% of grades using a computerised marking scheme to ensure results are not significantly higher than previous years.
It is claimed this means tens of thousands of pupils will not achieve the marks they had hoped for when they get their grades on Thursday.
As a result, they may not be able to attend their first-choice university unless they successfully appeal.
Those who appeal must be awarded a higher grade by 7 September to attend the university they have chosen.
In her letter to vice-chancellors, the minister also said universities should take into account a range of evidence when admitting students to courses.
She said exam boards are committed to doing all that is possible to resolve appeals for affected candidates by the 7 September deadline.
And in a bid to reassure A-level students and their parents, education secretary Gavin Williamson said: “I’m confident the system Ofqual has put in place is fundamentally a fair one, that will award the vast majority of students a calculated grade that genuinely reflects the grade they would have achieved.
“Provisional data published by Ofqual suggests that the number of As and A*s being awarded will increase compared to last year and moderation has ensured students from all backgrounds have been treated fairly.”