Schools across Aberdeen will be using the summer holidays to prepare for larger primary one classes after council chiefs removed a cap earlier this year, a union has claimed.
During budget talks in March, councillors agreed to remove the policy of only allowing a maximum of 18 children in any primary one class.
Now up to 25 will be allowed.
Ron Constable of the EIS teacher’s union said staffing budgets would be scrutinised.
The union is also analysing the results of a survey of their local members, and have received thousands of responses.
Mr Constable said: “The budget was in March so this won’t kick in until the new session, so we just don’t know what the impact will be yet.
“I think what will happen is that the schools will look at their staffing budgets in the new term.
“Our point of view is that EIS wants to see reducing class sizes. If there are less pupils in the class then teachers can focus their attentions further and spend more time organising groups and lessons – it is important especially as we are seeing more pupils with additional support needs in mainstream schools.
“Professors in their ivory towers don’t believe class sizes affect attainment but we don’t agree.”
Education convener John Wheeler has said that studies on whether class sizes affected attainment were mixed – and pointed out that countries like China and Canada have bigger classes but better results.