A proposed cut to special education spending in schools would be a disaster, the head of the Secondary Principals' Association says.
Documents show the government wants to greatly increase its spending on under-5s with special needs, at the expense of spending on school-aged children.
One of the areas it has singled out for urgent review is the Ongoing Resourcing Scheme for children with the most significant special needs, and in particular, the those aged 18 to 21 who use it.
Secondary Principals' Association president Sandy Pasley said secondary schools would not cope well with a cut.
"We haven't got enough as it is and to lose some funding from secondary sector would be quite dramatic for schools.
"We understand that it's good to put it into the early years but not at the expense of students in secondary schools because often the special education needs don't go away and sometimes they're exacerbated by adolescence."
Ms Pasley said the association would try and persuade the government not to go ahead with the proposal, which she said would be a disaster.
Kim Hall from Autism Action told Nine to Noon children under 5-years-old with autism needed more support - but funding for that should not be taken from school-aged children.
"Some children aren't diagnosed until they start school or even later, so that means those children already miss out on that vital funding at the start."
But Early Childhood Council chief executive Peter Reynolds said the change was a good idea.
"On paper it looks good. It's a shame we've got to wait another few months before we start seeing this thing roll out, but we'll be wanting to work very closely with the ministry to ensure kids who are struggling right now get some sort of relief in the future and their parents get that relief as well."
Mr Reynolds said research indicated early intervention was best for children with disabilities.
Minister of Education Hekia Parata said the government wanted to make sure its special education spending was as effective as possible.
"Evidence shows that providing learning support early in a child's life will have much greater impact," she said.
The update to special education was still under discussion. "We're at a proposal stage of the process. Any changes wouldn't come into effect until March 2017 at the earliest and will be managed incrementally and carefully to ensure ongoing support."
In parliament today, she said there was no proposal to cut overall funding to special education.
Ms Parata said a change in funding would ensure the $600 million spent was going to the right child at the right time.
"What we are looking at, based on a year's worth of consultation with the sector is, how do we redsign the service going forward, without comprismising the service for those currently in it. So there will be a long transition."
Ms Parata said special needs children would be getting the help they needed earlier.
National director of special education David Wales said the funding shift would happen gradually and depended on the success of early intervention.
Mr Wales said the ministry expected children would need less help at school if the ministry provided assistance earlier in their lives.
RNZ has previously reported that only about five percent of the $590 million spent each year on special education was spent in early childhood education, with the remainder going to the school system.
Documents from the government's review of special education show that imbalance could be turned on its head.
A graph (appendix 2) predicted special needs spending could peak among children aged three to five years, and then steadily decline.
Currently the spending rises sharply when children turn five and peaks when they are seven to eight-years-old.