The plan has been slammed by the Post Primary Teachers' Association, the Principals' Federation, the Education Institute and the Secondary Principals Association, and there are questions around whether the Government has the mandate to implement the change.
Vice president of the Principals Federation Paul Drummond told Radio New Zealand that charter schools overseas have done nothing to lift student achievement.
"Charter schools have been trailed overseas and where they are entrenched, despite their best intentions, they have done exactly the opposite, growing disparities between communities.
"We have questions around how they are going to staff these schools, what criteria they will use to select them, the basis of their curriculum, how they will be measured, and if they are not consistent with what the public system is then you have all the potential to actually make greater disparities and inequalities in the system."
Mr Drummond said New Zealand has a public education system which is 'second to none in the world".
PPTA president Robin Duff agreed, telling Newstalk ZB Stanford University research shows students do better academically at just 17 per cent of charter schools, compared to traditional schools.
"Simply foisting something from overseas as a scheme into our country without any thorough investigation or careful implementation suggests that a disaster is what we're going to have," he said.
Mr Duff said having charter schools in low-decile areas will place the country's most vulnerable young people in a worse situation.
Prime Minister John Key told Radio New Zealand National has always talked about "choice in education", and their support of the policy was just part of the nature of MMP.
"I don't think that the New Zealand voters are going to be up in arms because in a couple of communities in New Zealand we give some new model a go. If those students don't want to go there they are free to go to the existing school that they are at.
Mr Key rejected the suggestion voters may feel blindsided by the policy being sprung on them.
"There are thousands of schools in New Zealand, are you really telling me because we might trial in a couple of parts of the country at one or two schools to see whether they can deliver better results, somehow that is undermining the education system in New Zealand? I'm sorry but that sounds a bit far fetched to me."
Mr Key was not surprised people in the education sector were opposed to the plan, as they have a "vested interest" in the status quo.
"The real question you have to ask yourself is the current system serving the every child well. And I think the answer to that is no. There are plenty of failing schools, particularly in poor communities," he told Radio New Zealand.
Mr Key said charter schools here will not be the same as those failing abroad, and the integrated model has had good results overseas.
"It's a step towards more choice. At the end of the day it is my expectation that the vast overwhelming bulk of school sin New Zealand will continue to be as they are currently in the system, which is state schools. There will always be, I hope, independent schools, and some integrated schools, because I think they offer different choice, and this is another option, a different way of doing things."
"As we know with education more often than not the parents and the children have one objective and sometimes some in the sector are opposed to that. Just because they are opposed doesn't mean they are in line with what the parents and students want."
