They have bowed to pressure from local authorities for greater flexibility in organising smaller infant classes. Councils said they would be faced with accommodation difficulties if they were compelled to cut all P1-P3 classes to 30 or fewer.

Brian Wilson, the former Education Minister, acknowledged the problems early in his tenure and this week the Scottish Office formally instructed authorities to employ additional teachers where they cannot organise classes below 30.

A briefing on class size reductions in the Pounds 322 million Excellence Fund explains: “Ministers’ intention is that no child in P1-P3 will be in a single-stage class of no more than 30 pupils with a single qualified teacher. Larger classes will be permitted but in those cases there should be additional teachers.”

The Government is spending Pounds 48 million out of the total funding package over the next three years to cut class sizes.

Anne Wilson, director of education in Dundee and general secretary of the Association of Directors of Education, said councils were committed to smaller classes but faced problems finding the space in some schools. More classes would have to be created to lower the maximum size.

“We already have team teaching in Dundee at Downfield primary. There are 45 pupils in the primary one class and two teachers in the room,” Mrs Wilson said.

The policy, however, would have consequences for placing requests. A single extra pupil would force the council to employ an extra teacher. Councils would have to argue additional costs in the sheriff court if parents complained, Mrs Wilson said.