Nicola Sturgeon said she would have likely protested against the downgrading of pupils’ grades from their teachers’ estimates if it happened while she was at school – but will not reverse the decision now.

The First Minister said she “very possibly” would have been demonstrating against the Scottish Qualification Authority’s (SQA) moderation process that disproportionately impacted pupils from deprived backgrounds.

Ms Sturgeon said she understood many pupils will be feeling “aggrieved” after the SQA downgraded 124,564 results – almost a quarter of all entries – but refused to reverse the decision “because I don’t think that would be the right thing to do either”.

Defending what she described as “effectively statistical moderation”, Ms Sturgeon has argued results would not have been “credible” if the pass rate of the most-deprived pupils had risen by the 19.8% estimated by teachers before moderation.

If I had been in that position, I would feel aggrieved about that

The SQA revised down the pass rate of the poorest fifth of Scottish pupils by 15.2% compared to a 6.9% drop for those from rich backgrounds.

Asked whether she would have be joining the protest planned in Glasgow’s George Square on Friday morning if her own results had been downgraded because of her school’s historic standards, Ms Sturgeon said it was “very possible”.

“If I had been in that position, I would feel aggrieved about that,” she said.

“I totally understand, and sympathise and empathise, with any young person who is in the position of having a grade awarded by the SQA that is lower than the teacher estimate for that grade.”

But speaking at the Scottish Government’s coronavirus briefing, Ms Sturgeon told pupils the moderation was necessary to “command the confidence of colleges and universities and employers”, although she urged pupils to challenge their results if there has been “genuine individual injustices”.

“Every young person or their families who might be watching, who is feeling that understandable grievance right now that their award is lower than the teacher estimates submitted for them can go through the appeal process where their individual circumstances are looked at,” she said.

The deadline for submitting appeals for students waiting on a college or university place is August 14, and August 21 for all other pupils.

Appeal verdicts will be sent to school or colleges by September 4.

After the SQA revealed some of the methodology for changing teacher estimates on results day, social media was deluged by furious pupils and parents who believe that grades have been disproportionately affected because of schools’ previous performances and where they live, rather than their individual attainment.

Protest organiser Erin Bleakley, 17, said: “We deserve the same life chances as young people in affluent areas. How can anyone expect to close the attainment gap when your hard work can be wiped out based on your postcode?

“There needs to be recognition that living somewhere that is termed an area of deprivation should not be something that prevents young people from progressing to further or higher education.”