The survey comes as three parents today commence legal action in the Victorian Civil and Administrative Tribunal, alleging that the Education Department segregates children on religious grounds and discriminates against those whom parents opt out of the classes.

One of the parents, Sophie Aitken, says in her complaint her children were put in the corridor or given Lego to play with when she opted them out of special religious instruction at Ivanhoe East Primary.

''I am troubled by this segregation and the limitations it causes my children … Once [my son] was told by another child that he would go to hell because he didn't believe in God,'' she says.

Yarraville West Primary is one of 71 state primary schools in Melbourne's western suburbs that does not offer special religious instruction.

School council president Lisel Thomas says the school is relieved it has never been approached by an accredited instructor and therefore is not compelled to hold the classes under the contentious Victorian legislation. ''We have raised the issue of how we would feel if we were approached and basically told we had to deliver special religious instruction without us having a choice in the matter and that certainly concerned our school council,'' Ms Thomas said. ''We have children from a number of different religious backgrounds. We believe it is important for children to stay together and learn together rather than being segregated on the basis of their religious belief.''