Scotland's most senior education watchdog has told MSPs that the number of pupils in a class is less important than the quality of the teaching they receive.
The comments by Graham Donaldson, senior chief inspector of education, to the Parliament's education committee last week will be interpreted as an embarrassing dismissal of one of the Government's flagship education policies.
Ministers want to see class sizes in P1-3 reduced to 18 "as quickly as is possible", but they have met opposition from councils such as Labour-led Glasgow, which argues that research does not point to class-size reduction as the most effective means of raising attainment. Some authorities claim they do not have enough money to implement class size cuts.
The Government argues that, having provided the cash to maintain teacher numbers, falling rolls should take care of the rest.
But, as The TESS highlighted earlier this month, some councils with growing populations say hitting the target will cost them millions. The returns from our survey of council budgets this week (p4-5) confirm that progress is patchy at best.
Mr Donaldson's scepticism was revealed under questioning from Ken Macintosh, Labour's schools spokesman, who asked if the inspectorate had a role in monitoring whether class sizes were falling in the early years of primary. In reply, he explained class sizes would only figure in an HMIE report if they appeared to be impacting on learning: "If we were directed to do so, we would go into that.
"But, in inspections, we start from the quality of the child's experience and work back from it. If the way in which a school organised children into classes was an issue for their learning, that would figure in our report .
"Not to put too fine a point on it, the quality of what is done in a class is as important as, if not more important than, the size of the class."
After the meeting, Mr Macintosh said the senior chief inspector's comments validated Labour's position that quality education was about more than "arbitrary figures".
The Scottish Government, however, argues that smaller class sizes in the early years will allow "education professionals to stretch every child to achieve their full potential, providing them with the individual attention and support they need to flourish".
Larry Flanagan, education convener of the Educational Institute of Scotland, said: "There is no disagreement over the quality of the teaching process being key to success in the classroom.
"The main argument would be that smaller class sizes support and improve quality teaching and learning precisely because they allow more time for a teacher to work individually with the pupils in the class. They also clearly impact on issues related to discipline. Smaller class sizes don't eradicate poor behaviour, but they do make it easier to deal more effectively with disruption."