Act leader Don Brash wants top state schools including Auckland Grammar to have the freedom to set up franchises elsewhere, including blue-collar areas such as Porirua.
But the Principals' Association says former Auckland Grammar principal Sir John Graham has already investigated the idea and found it unworkable.
Dr Brash launched Act's education policy yesterday, saying "successful and established" state schools should be allowed to become "trust schools".
They would be exempt from Education Ministry management and "given control over their own affairs".
"Why should there not be an Auckland Grammar campus in Porirua?"
But the head of the Secondary Principals' Association, Patrick Walsh, said the plan was "educationally flawed and doomed to failure".
"Unfortunately I think Dr Brash is making an analogy between schools and a fast-food franchise such as McDonald's."
Mr Walsh said former Sir John Graham was appointed as a commissioner to a school in South Auckland.
"To his credit he realised that he couldn't import an Auckland Grammar model into South Auckland, that the nature of the students, the learning environment, is completely different and you need to shape an educational model that works for that particular school."
Act also says parents should be able to use their child's share of taxpayer education funding "at the school of their choice, be it independent, integrated, or state" and should be able to use a ministry website to compare schools' performance.