Nearly 85 per cent of people who took part in the polling commissioned by the Australian Education Union, said proper funding of public schools was important to them when deciding how to vote in the May 18 federal election.

This view was shared by 78 per cent of Liberal supporters in the poll of 660 Gilmore voters conducted in April.

Almost 65 per cent of all voters in Gilmore want to prioritise funding for public schools over extra funding for private schools.

"The Morrison Government's plan to cut $917 million cut from public schools in New South Wales while delivering big tax cuts to high income earners is the opposite to what the public wants," NSW Teachers' Federation acting president Henry Rajendra said.

"They want to see our children in public schools in Kiama, Ulladulla and Nowra put first, not unaffordable tax cuts that will lead to $40 billion in government spending cuts every year just to pay for them."

Almost 50 per cent of Gilmore voters also said the Coalition's $4.6 billion special funding deal to private schools makes them less likely to vote Liberal.

"The Federal Coalition's record on education and public schools is a poor one," Mr Rajendra said.

"First Tony Abbott tried to cut $30 billion from schools, and then Malcolm Turnbull and Scott Morrison reduced that to a $14 billion cut for public schools.

"That meant schools across Gilmore, from Tomorong to Tuross Head, received less funding for high-needs students, such as those with a disability and those from disadvantaged backgrounds."

He said by contrast, public schools in Gilmore would receive an extra $21,610,000 in funding in the first three years of a Shorten Labor Government.

Early voting centres opened on Monday.