Average primary school class size stands at 23.5 pupils according to new Scottish Government statistics - static since 2016 but up from 22.8 pupils in 2007.
The figures also show that only 12.3 per cent of children in primary one to three are in small classes, despite an SNP pledge to make all early years classes 18 pupils or fewer. This has fallen from 21.6 per cent of pupils being taught in small classes in 2010.
However pupil numbers have also grown - up 4738 from 2018 - resulting in the teacher-pupil ratio remaining at the same level for the last three years.
Today, speaking at St Peter's primary school in Edinburgh, Deputy First Minister John Swinney said: “I am delighted to see teacher numbers continuing to increase, with levels at their highest in a decade and the number of primary teachers being the highest since 1980.
“Since 2006 there are now fewer P1-P3 pupils in large classes of 31 or more, which is particularly important as helping children in the early years is crucial if we are to close the attainment gap between the most and least deprived."
He added: "Since taking power in 2007, over a decade ago, the SNP has presided over a continual decline in the quality of education in Scotland - failing to deliver on promises they made, and frankly, that is a disgrace. The pupils, teachers and parents of Scotland deserve better than the managed decline they are being offered by the SNP.”
Scottish Liberal Democrat education spokesperson Beatrice Wishart said: “The SNP came to power telling people that P1-P3 pupils would be in small classes. More than a decade on and this is being achieved for just 12 per cent of children. It has failed 147,000 children this year alone.
“Meanwhile, the average class size remains at a record high. Both teachers and pupils have been let down by the SNP government."
He added: "Add to that the increases in class sizes and the pupil-to-teacher ration and you can see why this government picks random years to compare to, rather than measure their own time in office.
"Teachers are more stretched than ever and John Swinney can try to deflect as much as he wants, but if he is serious about closing the gap between pupils from the richest and poorest background, he had to admit the mistakes he’s made and get teacher numbers back to where they were."
The Educational Institute of Scotland - the teachers' union - said that there was "much to be welcomed" in the statistics, though there were areas of "significant concern".
EIS General Secretary Larry Flanagan said the headline number of more teachers in schools was balanced by the rise in pupil numbers. He added: "The end result is that pupil/teacher ratios are at a standstill and average class sizes remain unchanged.
"If we are to address the excessive workload burdens that are currently being placed upon Scotland’s teachers, we need to employ more teachers in our schools in order to reduce class sizes and enhance the learning environment for pupils.”
Mr Flanagan said the EIS was also concerned that the proportion of the 2018/19 probationer teachers with a full-time permanent post at the time of the year was 48 per cent, down from 55 per cent from the previous year and a "continuing decline" in teacher numbers in early years which has fallen from 1200 in 2014 to 798.