NICOLA Sturgeon is not obligated to sack John Swinney if a vote of no confidence in the Education Secretary is passed, the Presiding Officer has said.

Ken Macintosh of the Scottish Parliament explained that the motion of no confidence tabled against the Education Secretary would have to be debated if it is backed by 25 or more MSPs, but it would be an "expression of Parliament's opinion" - not legally binding.

Both Scottish Labour and the Scottish Tories say they will declare no confidence in Swinney, with the two parties made up of a combined 54 MSPs.

Scottish Labour tabled the motion after widespread criticism of the system to award grades to pupils in the absence of exams due to the coronavirus lockdown.

READ MORE: First Minister tells pupils she will fix SQA row without appeals

The SQA moderation process saw 26.2% of grades changed during the moderation process based on criteria that included schools' historic performances - with a total of 124,564 pupils' results downgraded.

Pass rates for pupils in the most deprived areas were reduced by 15.2%, compared with 6.9% for pupils from the most affluent backgrounds.

The Scottish LibDems and Scottish Greens are yet to state whether they will support the motion.

The motion was tabled yesterday morning, meaning a debate is not likely to take place before Wednesday as MSPs are normally given two days' notice ahead of a no-confidence vote.

Asked about the process of a motion of no confidence would work, Macintosh said: "It requires 25 signatures, once it reaches 25 signatures it must be debated, the [Scottish Parliament's Business Bureau] must find parliamentary time for it to be debated."

He added: "Motions of the Parliament are an expression of the Parliament's will - an expression of the Parliament's opinion.

"So the consequences are for MSPs, politicians and the government to determine, not for the Parliament itself."

Swinney and Sturgeon initially defended the system, stressing that the appeals process would allow eligible pupils to challenge their results and arguing that it would not have been "credible" if teachers' estimates were not downgraded.

But following protests from pupils in Glasgow and cross-party criticism of the system, the First Minister announced that Swinney would address Parliament today and "rectify" the situation.

She said that pupils who had their exam results downgraded will not all be expected to appeal against them, apologising to them at yesterday's coronavirus briefing.