Douglas Ross’s party said data obtained through Freedom of Information legislation shows pupils were more harshly marked this year than in 2020 when teacher estimates alone were used to judge grades.
Results from five local authorities show a marked decline in pass rates in several subjects when compared to 2020, with many more in line with grades from 2019.
Oliver Mundell, the Scottish Conservative’s education spokesperson, said this year’s system was “just as unfair and flawed as last year”.
He said: “This early release of results shows that pupils in councils across Scotland have been marked more harshly than in 2020.
“They have faced double the disruption of last year’s pupils, who themselves had their learning experience upturned, yet the signs show that has not been fully factored in.
“A reduction in pass rates across the board compared to 2020 is another clear indicator that ‘teacher judgement alone’ did not decide grades, as the SNP insisted.
“What happened in reality is not what young people were promised. They did sit exams and teachers have not decided grades entirely on their own.”
However, the Scottish Government said the opposition were wrong to “play politics” with pupils, arguing the Conservatives should “congratulate learners and teachers”.
The Scottish Government has come under significant pressure around its implementation of the ‘alternative certification model’ for exam results this year.
The system, which saw pupils sit exams in all, but name in school, was said to be based on teacher judgement and ‘demonstrated attainment’.
However, councils have said school’s historical data would also be used to assess any grades which appeared to be outliners, leading to concerns that grades could be lowered below the grade provided by teachers.
Data analysis by the Scottish Conservatives of pre-release pass rate data from five councils – Highlands, Borders, South Ayrshire, Dumfries and Galloway, and Aberdeenshire – suggests overall grades will be around 5 per cent lower than in 2020, but higher than 2019.
However, there are clear variations by subject, with all councils apart from South Ayrshire seeing pass rates in Maths drop below 2019 levels.
Mr Mundell said students faced a “postcode lottery” and the scandal showed the need for a return to traditional exams.
He said: “This early release of results strongly suggests that the SNP have used historical data to knock down grades. It looks like this year’s system is just as unfair and flawed as last year.
“Pupils seem to have faced a postcode lottery. We warned this could happen when it became clear that young people would be sitting exams under inconsistent conditions, with wide variations in difficulty from council to council and even school to school.
“These back-to-back years of chaos are the strongest argument in favour of retaining and restoring traditional Scottish exams. The deep unfairness young people have suffered cannot become an annual event.
“Before the SNP rush to abandon Scottish traditions and remove one of the last hallmarks of our unique education system, they should consider how shambolic the exams system has been over the last two years.”
A spokesperson for Shirley-Anne Somerville said: “It’s disappointing to see opposition parties attacking results before they are even out and trying to play politics with Scotland’s school pupils, rather than engaging constructively to celebrate the achievements of our young people under extraordinary circumstances. I congratulate learners and teachers – the opposition should do likewise.
“This year’s more flexible approach will deliver fair, credible and consistent results based on teacher judgement of the evidence of each pupil’s attainment. There are no algorithms; no historic results defining awards, no SQA veto on results – and the most comprehensive appeal process ever as a safeguard.
“Scotland’s industry leaders and employers have also made it clear that they recognise and value the qualifications achieved by young people this year as much as any other year.”