The New Zealand Educational Institute is dubbing the ACT party's education policy as supermarket schooling.
ACT has announced it wants to give all public schools the choice to become charter schools.
ACT leader Jamie Whyte said the policy would involve opting out of Ministry of Education control, and setting their own course, with schools bulk funded according to enrolments.
But the Educational Institute says that's crackpot nonsense and the police would harm children's education.
Its president Judith Nowotarski said ACT wanted to push children through privatised education, as though they were commodities.
She said it had been internationally proven that charter schools were unreliable and the National-led Government should reject the policy.