THE Victorian Education Department is forcing public primary schools to run Christian education classes taught by volunteers, angering parents and schools that do not want to host them.

An email exchange, obtained by The Sunday Age, reveals the department told one parent that his school ''must'' keep its Christian religious instructor whether it wanted to or not.

Email from Education Department to parent Tim Heasley.

A number of Melbourne primary schools have questioned whether students should be taught about Christianity. But the department and Christian religious education provider Access Ministries says they have no choice.

This comes as the Humanist Society of Victoria takes legal action against the department, claiming children who opt out of ''special religious instruction'' are being discriminated against.