The electorate with the most projects is Monaro, held by Deputy Premier and Nationals leader John Barilaro, who faces a fight defending his slender margin of 2.5 per cent.

One of the projects in Monaro is a new special needs school, which Mr Barilaro has been pushing for despite Department of Education advice previously indicating it was not a priority.

The NSW government announced on Monday that 123 schools will be built or upgraded across NSW with $2.2 billion in new funding to address overcrowding fuelled by a surge in student enrolments.

The projects are slated to begin within the next two years, meaning they will likely be under way in time for the March 2019 election.

An analysis shows that 56 are in Liberal-held seats and 21 in Nationals-held seats, for a total of 77 projects in Coalition-held electorates.

This compares with 39 in Labor-held seats. Four projects have been announced in Greens-held seats and three in seats held by Independents.

Monaro is in line for seven projects, exceeding even the number earmarked for the Sydney growth areas of Riverstone and Camden, with six each and Ryde, with five.

Labor's education spokesman Jihad Dib accused the government of "playing politics" with children's education.

"Class places should be allocated on a needs basis – such as those areas that are undergoing the greatest growth – not in the electorates where the Liberals and their junior partner are under the greatest threat," he said.

But Education Minister Rob Stokes said the accusation was "ridiculous".

"Clearly the opposition doesn't understand that the parties in government represent more electorates with more schools, more people and more growth – hence more school projects," he said.

Mr Stokes said the Coalition held electorates in many of the state's high-growth areas "including new subdivisions and urban renewal areas".

"Demographic projections in these areas confirm the need for more investment in education infrastructure in these areas," he said.

He said Monaro needed to be "assessed in context".

"One of these schools is a School for Specific Purposes while a number of other upgrade projects are small in scope," he said. "Queanbeyan has a growing population due to its proximity to Canberra."

Mr Barilaro said Monaro was "often overlooked when it comes to establishing specialist services".

"For some time now, I have been lobbying the NSW government to build a School for Special Purpose (SSP) in Queanbeyan with specially designed programs that meet the requirements of children with a disability," he said.

"Currently we have no such facility in the Monaro for special needs school students."