The Education Minister has admitted private schools could be about to get more public money.

Hekia Parata told The Nation she's considering big changes to the way schools are funded, including greater discretion to spend less on teachers.

At the country's most prestigious and prosperous schools, plans to change funding for private education could see public money make them richer still.

Public funding for private schools is currently capped at $41 million a year. The Ministry of Education wants to scrap that limit and give private schools a set amount per student instead.

The Minister admits that could cost the public more, "if that's what New Zealanders think is fair".

Private schools argue an increase is fair.

"All of our parents are taxpaying parents, and our schools pay more in GST than in fact we receive in funds from the Government, so it's net gain, actually, for the whole of the country," says Diocesan School for Girls principal Heather McRae.

But Labour says state schools will suffer.

"The priority for funding should be our state schools, not more money going into private schools, which are effectively private businesses," says Labour finance spokesman Grant Robertson.

The ministry is also considering a change to the way all schools receive their funding.

Global budgets would give schools more flexibility, so, for example, they could choose to spend less on teachers and more on other operational costs.

"We're saying, 'How do we give greater flexibility to principals and boards about what teaching staff they need?'" says Ms Parata.

Critics say global budgets are essentially the same as the "bulk funding" policy of the 1990s, one that drew a decade of regular protests, before being dropped in the year 2000.

"They might want to give it a different name, but it's the same thing," says Mr Robertson. "If it walks like a duck and quacks like a duck, it is one."

The Post-Primary Teachers' Association says the move would remove all guarantees over teacher numbers and lead in the end to bigger class sizes. The Government is preparing to consult the sector, and the PPTA is preparing for a fight.

Newshub.