CLASS sizes in Oxfordshire’s primary schools are slowly creeping up.

Last academic year one primary class in the county was crammed with 37 pupils, and another with 36, the latest government figures reveal.

Both were Key Stage 2 classes (ages seven-11), staffed by just one teacher.

The Department for Education statistics, which only include state schools, do not specify which schools or school those classes were at.

Though the number of largest classes has stayed constant for the past three years, with two classes consistently in the 36+ category, the average primary class size has gradually increased.

A Key Stage 1 (ages five-seven) class in Oxfordshire now holds 26.1 pupils on average, compared to 25.7 in 2010.

For Key Stage 2, the figure has crept up from 26.1 in 2010 to 26.7 last year.

But Lynn Knapp, headteacher at Windmill Primary School in Headington, said she had not noticed a change.

She said: “Our numbers are pretty stable.

“We always aim to be about 30 [in a class], which, as we are quite a popular school, can be pushed to 31.

“On the whole we haven’t had to increase class sizes.

“I think classes of 20 would probably be optimum, but 30 is certainly manageable.”

Campaigners have previously warned that the teacher recruitment crisis would bring bigger class sizes.

Legislation limits Key Stage 1 classes to 30 pupils for one teacher, though there are exceptions. There is no limit for older children.

Last academic year four Oxfordshire state primaries had a teacher-pupil ratio exceeding 30, compared to just one the previous year.

The ratio is calculated by dividing the number of full-time teachers by the number of pupils, but the figure does not translate into class size.

Topping the table at a ratio of 36 pupils to one teacher was St Thomas More Catholic Primary School in Kidlington, but headteacher Breda Bowles was concerned that the statistic was inaccurate.

She said: “We’ve only got one class at 30.

“It would be quite shocking if there were that many pupils [36] in our classes – I would be horrified.”

Wootton St Peter’s CE Primary School near Boars Hill had a pupil-teacher ratio of 34:1, but headteacher Fiona Rose also questioned this figure, noting her biggest class was also of 30.

She added: “I’ve been here two years and when I arrived there was a class of 34.

“Anything over 30 is pushing it but our budget will hold two part-time teachers, so our largest class has got a full-time and part-time teacher.

“It’s not an issue for me but I know some schools don’t have that luxury.”