Bulge classrooms are a “better” than bigger class sizes, according to the borough’s education portfolio holder.

Councillor Reuben Thompstone says he would rather see schools expanded either permanently or temporarily than squeeze more bodies into existing classrooms.

The Golders Green representative spoke to the Times Series on a visit to Martin Primary School, one of seven primary schools undergoing permanent expansions to meet rising demand.

The East Finchley school, in Plane Tree Walk, underwent a £3.3million summer upgrade to provide 120 extra school places over the next four years.

The authority needs to find more than 3,360 school places in the next four years but Cllr Thompstone says the authority is working hard to meet the demand.

He said: “It is difficult to say how close we are to the targets because they are not so simple to identify.

“Bulge classes are not ideal – we would rather have long-term expansion but where we don’t have the means it is a problem.

“I understand parents are going to have concerns about class sizes but I think we’re in a better position if we have bulge classes and expansions than bigger groups in one class.”

Barnet Council has spent £88million since 2009 on permanent expansions and rebuilds at primary and secondary schools and has pledged a further £49million to future projects.

Cllr Thomstone added: “We choose popular schools and those we know are operating well. It is an ongoing challenge and one our officers are ready to deal with. We have been very prudent as a council over the past few years and now we have the finances to do this.”

Martin Primary was rated outstanding by Ofsted inspectors following its last assessment in December 2011.

Helen Morrison, headteacher at the school for six years, believes the increase in the school’s capacity should not affect performance.

She said: “It doesn’t matter how big a school is, it becomes outstanding in the way it is led and taught. I don’t see why we can’t be a three-form-entry school and maintain our outstanding status.

“We have a superb relationship with our parents and they are kept well informed and have been very supportive of the expansion.

“For me it is about meeting our local community’s needs and providing local school places for local children.”