The chair of the Secondary Principals' Council says funding guidelines for schools may have the unintended consequence of increasing the divide between wealthy and poor.
In 2013 the Education Ministry made it clear that schools could not oblige parents to contribute to school costs or charge for activities that are part of the curriculum.
Allan Vester said there was a possibility that schools would not put on courses because they ran the risk of incurring financial losses.
He said it could cause an increasing divide between the kinds of opportunities that the schools could offer according to the socio-economic status of the community where the children lived.
Mr Vester said there was already a significantly growing divide between schools in New Zealand and these regulations had the potential to acerbate that.