Nicola Sturgeon has defended her Education Secretary over claims he secretly ordered an inquiry into falling pass rates at Higher, arguing "the Tories are incapable of paying attention".

Scottish Conservative leader Jackson Carlaw started First Minister's Questions by asking about an investigation requested by John Swinney in the wake of the Higher pass rate falling from 76.8 per cent to 74.8 per cent last year.

The First Minister said Mr Swinney had told Holyrood's Education Committee about his plans for a review and the Scottish Government would "publish findings as and when we have them".

READ MORE: Asylum seeker who feared death if deported earns top Glasgow University offer

Addressing suggestions Mr Swinney had "secretly" called for the review, she said the Scottish Conservatives were "flatly wrong and I don't think that is acceptable".

Mr Carlaw said: "In September, while publicly berating operation critics, the Education Secretary privately commissioned his officials to probe the increasing failure rate at Highers."

Ms Sturgeon responded: "The Deputy First Minister actually informed the Education and Skills Committee of this Parliament on November 27 of the analysis of the 2019 SQA results that he intended to carry out.

"I don't think that the Deputy First Minister can be held responsible if the Tories are incapable of paying attention to what's going on in Parliament."

Following a shouted interruption from the debating chamber's public gallery, Mr Carlaw described Ms Sturgeon's answer as "slippery".

"It's not just Conservatives, it seems that the whole world misunderstood what the Cabinet Secretary was trying to say", he said.

"In August last year, we learned that the number of students achieving A to C at Higher had fallen.

"Mr Swinney promptly attacked us for daring to suggest that something might be wrong with his handling of education.

"Then over Christmas, we learned that he had - at the same time - asked his officials to find out what's going wrong."

Referencing a letter to Tory education spokeswoman Liz Smith, Mr Carlaw added: "Mr Swinney declared that he doesn't need to explain himself to this Parliament because there's nothing new to say."

READ MORE: Emotional problems among schoolgirls ‘could be linked to social media’

Ms Sturgeon maintained her deputy had told MSPs on the Education Committee and acknowledged "we know in Scottish education there is more work to do, which is why it remains the top priority of this Government".

"Jackson Carlaw has stood up in this chamber and suggested that John Swinney secretly commissioned an analysis of the 2019 exam results," she said.

"John Swinney has pointed out the fact - and I have done it again today - that actually he informed the Education and Skills Committee on November 27 that he had asked for such an analysis."