The Green Party is calling for an inquiry into charter schools and questioning the impartiality of a group appointed to set up the new schools.
Former Act Party President Catherine Isaac, who was third-ranked on the Act Party list and considered a potential leader of the party, has been confirmed as the chair of the working group.
She is joined by former Christchurch Mayor Vicki Buck, who has established two "innovative" schools in Christchurch, and five others.
Green Party education spokesperson Catherine Delahunty said the appointment of Buck and Isaac raises real questions about how neutral the group will be.
She has also called for an inquiry into the effectiveness of charter schools before they are implemented.
"We need a careful and objective inquiry into the benefits, or not, of the charter school idea rather than launching headlong into some risky scheme and then tinkering with the problems when they arise," Delahunty said.
"The Green Party has real concerns about the damage the charter schools experiment could wreak on the children who get caught up in it, and the syphoning of precious funds away from schools that need them now."
Labour education spokesperson Nanaia Mahuta has also slammed Isaac's appointment to the group.
"Ms Isaacs' official appointment will see the charter schools plan rammed through with little regard for best practice in the New Zealand context. Expect a collision course," she said.
"There has been a lot of hype from the Government about charter school models lifting achievement. But research shows that results are variable across schools, inconsistent amongst specific learner groups and there are serious quality issues that cannot be neglected."
Education Minister Hekia Parata and Associate Education Minister John Banks announced the appointments, which follow a promise to establish charter schools in south Auckland and Christchurch as part of the confidence and supply agreement between National and Act.
"The group will consult with a wide range of people, including the teaching profession, unions, parents, businesses, communities and educational experts from around New Zealand and around the world, to determine what charter school model will work best for New Zealand," Parata said.
The other appointments to the group were Tony Falkenstein, founder of the Onehunga Business School and chief executive of Just Water; Michael Hollings, chief executive of the Correspondence School; Hana O'Regan, Dean of Faculty of Maori at Christchurch Polytechnic; Margaret Southwick, an academic expert in health and education outcomes for Maori and Pasifika; and John Taylor, former head of King's College and Rathkeale College and current director of alumni relations at Auckland University.
The board would meet for the first time next week and lay out a programme of work that would culminate in advice to Banks on how best to implement the New Zealand model of charter schools.
"These are high quality individuals who bring an impressive mix of skills and experience from the education and business sectors," Banks said.
"These include a proven track record of innovation in education, an understanding of the needs of disadvantaged communities, as well as a thorough understanding of Maori and Pasifika needs."
Isaac had served on a number of boards, including school boards of trustees and was a member of the welfare working group in the Government's previous term.
"The charter school initiative is one of the most exciting initiatives we have to contribute to solving our most urgent educational problem; the long tail of underachievement."
The charter schools plan has sparked controversy with critics pointing to similar models overseas that have had mixed results.
Chief executive of the Education Ministry, Lesley Longstone, played a key role in setting up the similar "Free Schools" model in the United Kingdom.
According to official documents, charter schools here would have "freedom from some of the law and policies that apply to state schools".
They would use their "own teaching practices" and pay teacher salaries on performance. A charter school would also be able to "manage itself" or "contract school operations out".
Officials have advised the Government that evidence on the success of US charter schools is "mixed".
"They have not consistently led to significant increases in achievement among lower performing student populations," officials advised last year.
Officials have cited a US study which found 17% of charter schools provided better learning opportunities; nearly 50% had results no different from local public options; and 37% delivered results worse than what was available at public schools.
Banks said the New Zealand model would draw on the "best practice of overseas models".