THE CHIEF executive of the SQA will be grilled by MSPs over the exam moderation fiasco.

Fiona Robertson will appear before Holyrood’s Education Committee on Wednesday and will face questions over an angry row that has emerged after more than 120,000 grades were downgraded by the SQA after teacher estimates were drawn up to replace this year's exams.

READ MORE: SQA under fire after thousands of pupils' grades lowered based on schools' past performance

The row has emerged after a school’s past performance has been taken into account in the methods used to downgrade results – amid concerns those from more deprived areas have been hardest hit.

Ms Robertson will be quizzed over the issues on Wednesday.

Clare Adamson, convener of Holyrood’s Education Committee, previously raised concerns over the issue with Ms Robertson – warning that “transparency on the alternative processes is essential to instil confidence in the system being used this year”.

READ MORE: SNP division over exams grows as ministers urged to reverse SQA downgrades

In a letter to Ms Robertson, Ms Adamson warned there could be “a large number of appeals”, that “would cause a capacity issue for secondary school teachers who would also be undertaking intensive preparations for the re-opening of schools on a phased basis the following week”.

She added it is likely the appeals process will “take longer than usual”, holding up confirmation for university places.

The Scottish Liberal Democrats called for Scotland's public spending and management watchdog to investigate the SQA process.

Leader Willie Rennie said John Swinney should turn to Audit Scotland for help.

He said: "The Education Secretary and the SQA were warned for months that their moderation process would embed inequality and potentially damage the prospects of bright pupils for life.

"The SQA refused transparency, scrutiny and discussion of the methodology that has led to this injustice on a such large scale. Audit Scotland should now look into whether this methodology was fit for purpose.

“It is unacceptable that pupils have been downgraded for exams they didn’t sit based on the historical performance of their school. We must have confidence in the process used by the Scottish Qualifications Agency especially if next year’s exams are cancelled too and this exercise has to be repeated.

“A thorough investigation by Audit Scotland should be done to rectify these problems and ensure lesson have been learned.

"Young people have made tremendous sacrifices over the past six months. They do not deserve to see their futures carved up by a computer algorithim based on where they happen to live."