The Green Party believes all young people should have access to higher education, regardless of their religious background.
Education Review Office officials have been asked to appear before a select committee, to explain why the school at the South Island Gloriavale Christian sect has been given the tick of approval.
Education spokesperson, Catherine Delahunty, is worried young pupils there are being denied a chance to go to university.
"We have an obligation to offer quality education in both state and private schools and make sure that they have choices," says Ms Delahunty.
"Some of them would be really happy to leave school at 16 and have children at early age but that should be their choice, not the only option available to them in their education."
Ms Delahunty says there is a clear difference between the ERO's report and what's been said in the media.