The government's wide-ranging change agenda for the education system is worrying the school and early childhood unions, the NZEI and the PPTA.
The Post Primary Teachers Association says changes are aimed at paving the way for privatising the school system - a claim denied by the government - and the Educational Institute has warned the changes must be driven by the needs of children, not by ideology.
The unions are holding their annual conferences this week; the PPTA in Wellington and the NZEI in Rotorua.
The conferences are taking place amid a raft of proposed changes across the sector, including school and early childhood funding systems, special education and the Education Act.
The unions' leaders said the government's reforms were 'huge' and covered most aspects of the school system.
The changes were the most significant in more than 25 years, NZEI president Louise Green said.
"They change the way schooling and early childhood education are delivered, so it changes the system, and these are the biggest changes since Tomorrow's Schools was introduced in 1989," she said.
Ms Green said the changes could harm the public education system.
"We pride ourselves in New Zealand on high quality public education and we're concerned that many of the changes start to undermine that, because they think more about the system and less about the child."
PPTA president Angela Roberts said some of the changes appeared to be paving the way for privatisation of the school system.
"When you start connecting all of those bits up, it's a very, very clear agenda," she said.
"This is about privatisation and giving corporate entities, to use the government's own language, access to our schools."
Ms Roberts said companies were geared to make profit, and nobody should profit from the school system.
"That will absolutely undermine and destroy what is a world-class system."
But in a statement, Acting Education Minister Anne Tolley said there was no plan for privatisation.
"The changes being proposed for the future of our education system have nothing to do with laying the path for privatisation of education.
"Any suggestion that they are makes it quite clear that there is a lot of misinformation being put out at union events."