The new Education Minister has planned action to stamp out "covert" fundraising by schools such as marking up uniforms to make a profit.

Chris Hipkins told the Herald the new Government's overall objective was to make sure a state school education in New Zealand was free.

"Which is what the law guarantees ... the reality is and every parent in the country knows at the moment that's not what they are getting. Parents are being asked to pay more and more of the cost of their kids' education," Hipkins said.

"At the moment, particularly around things like the big mark-ups on uniforms, schools are finding ways of getting around the rules that they shouldn't be asking parents to pay. We are going to be taking a much firmer line on that.

"If you look at the variability and cost of uniforms between schools it is clear that some schools are making quite a lot of money."

As well as expensive school uniforms, Hipkins said he had concerns about schools charging compulsory fees for activities that are part of the core curriculum, such as seeing a play students will be assessed on.

Schools can only exclude non-paying children from activities or events that aren't part of the core curriculum, like a sports or social event or camp.

Hipkins said he would sit down with the Ministry of Education to work on guidelines to be provided to state and state-integrated schools, making clear such "covert" fundraising wasn't allowed. It was still to be determined when those would be circulated, or whether the guidelines could be as specific as advising what an acceptable margin on uniform sales was.

Labour recognised that it needed to fund schools properly to remove the impetus for unacceptable fundraising efforts, Hipkins said. It will give schools that agree to stop asking for voluntary donations from parents $150 per student.

Hipkins said he expected more than half of all schools to sign up to that scheme, but it was still unclear when it would kick off.

"I can't give a timeframe around implementation of that, whether it will be during the year next year or from the beginning of the following year."

Avondale College principal Brent Lewis said his school, with a roll of about 2700, ran its own uniform shop to keep prices down, but it wasn't as simple as saying any margin above the suppliers' price was profit.

"Schools do need to make some margin over cost. Because they will have $300,000 or $400,000 worth of inventory lying on the shelf.

"It is a little more complex than the way it is portrayed ... we had a pair of shorts that we introduced that the youngsters really wanted 15 years ago. Then suddenly every single girl in the 7th form decided they were hideous, and we will never sell another one of those shorts."

Lewis said the Avondale board was carrying out a uniform review, including a proposal to cut the price of PE uniforms by $15 to $20.

"We don't want to make a profit. We are always trying to keep the price down. And if we start making a profit we adjust."

Lewis said he could understand why there was concern about uniform costs, and one potential solution was to ask school auditors to look at margins on uniforms over a number of years. Avondale and other schools provided support for families in hardship.

Consumer NZ chief executive Sue Chetwin said she welcomed Labour's pledge to draw up guidelines for schools. Consumer has in the past raised concerns about schools striking exclusive supplying arrangements on uniforms, stationery and digital devices.

"A code of ethics around it would be really good," Chetwin said.

A Weekend Herald price comparison carried out earlier this year found parents with a boy and girl at secondary school could pay $700 for just the uniform basics.

The Commerce Commission has received complaints about the costs of uniforms and stationery and issued procurement guidelines, recommending schools make the supplier-selection process transparent and tell parents why deals were entered into. It is illegal to enter an agreement that substantially lessens competition in a market.

The Labour-led Government will also establish funding to help students access mobile digital devices for bring-your-own-device (BYOD) learning. Hipkins said details were still being worked through but there would not be a one-size-fits-all approach.

FREE EDUCATION?

• Education at a state school is meant to be free, although parents must pay for school uniforms, stationery and some extra activities.

• Schools can only exclude children from extra activities if it is not part of the core education curriculum, like a sports event, camp or social event.

• Labour says some schools are making large profits by marking up uniform prices, and it will issue guidelines to stop this.