An Auckland state school says most parents want its Christian education programme for five- and six-year-olds to continue.
A woman taking a complaint to the Human Rights Commission about the programme at St Heliers School says the classes are a form of indoctrination.
Two parents have now complained to the commission to try to stop the school giving religious instruction to Year 1 and Year 2 pupils.
Melissa Muirhead says while she would be happy for her children to be exposed to a variety of religions, Christianity is the only one being taught at the primary school and that amounts to discrimination.
"The school promoted it as a values-based programme, but it's not. It's actually very much Christianity and (coming) from an angle which I think is indoctrination of children at a very vulnerable age."
The head of the school's board of trustees said a survey of parents at the end of last year found more than two thirds wanted the classes to continue, with just under a fifth against them. Gary Ivill said only 12 of the school's 221 children in Years 1 and 2 have opted out.
Parent Roy Warren, who has also made a complaint, said his child comes home repeating Christian beliefs and is only learning about one religious viewpoint.
Another father, Maheen Mudannayake, said he was disturbed to see a volunteer instructor setting up a mock communion with fruit juice and rice cakes at the state school.
Mr Mudannayake, a Buddhist, removed his children from the optional classes, and said his children are left to draw or do menial tasks during the sessions.
"For them, it's basically like detention. They hate being away from their peers and they find it hard to understand why they're away given they're only Year 1 and Year 2, so these are five- and six-year-olds we're talking about."