Labor calls for more schools in NSW

More Sydney children face being locked out of schools in their local area unless the NSW government invests in education, the opposition warns.

Labor leader Luke Foley says the Baird government is "hell-bent" on selling off public land to property developers despite skyrocketing enrolments and already overcrowded schools.

He says a "baby boom" means the state has to find 300,000 extra school places for children during the next 15 years.

"The government's insistence in selling off the best public land to property developers each and every time means they're failing our schoolchildren," Mr Foley told reporters in Sydney on Wednesday.

Mr Foley cited the sale of the Lidcombe Motor Registry in western Sydney to property developers while the nearby Lidcombe Public School increasingly relied on demountables to house its growing student population.

He challenged Premier Mike Baird to install schools at soon-to-be-vacated sites including the Powerhouse at Ultimo and Sydney University's Cumberland College.

"If we don't use public land to find the school places we need, the cost will be ever-growing school classrooms, more and more demountables, and perhaps class sizes increasing," he said.

But Education Minister Adrian Piccoli said the government had invested $1 billion on new or refurbished classrooms and almost $4 billion on capital works, which included new or bigger schools.

"The NSW government is making a massive investment in public education," Mr Piccoli said in a statement.