Leisa Cooksey has collected more than 150 signatures supporting the government's trial of ethics classes and is calling on parents who support the trial to voice their view.

The NSW Parents and Citizens Association has labelled the term two trial a "resounding success" and called for it to be rolled out statewide.

Conversely, at Warners Bay High, church groups and business have come together to build the school a designated scripture building.

Reports suggest up to one in four children in state schools do not attend weekly scripture lessons run by religious groups.

Department policy is that during that time, withdrawn students should not be given activities that compete with scripture or alternatives, such as ethics, civics or general religious education.

But students can complete homework or reading.

"If your children do not attend scripture they're not entitled to any structured meaningful education or learning during that time," Ms Cooksey said.

"Those children have the right to explore moral and ethical issues just as much as those in scripture."

Ms Cooksey, an atheist, said she was spurred into action after her seven-year-old daughter, Zoe, who does not attend scripture, came home in tears because another student said they couldn't be friends because "she didn't believe in God".

Ms Cooksey said it was, in part, because of the "opt-out" nature of scripture classes.

"People do not want their children to feel left out so the vast majority will just let their kids attend, there's no viable alternative," Ms Cooksey said.

Ms Cooksey said she did not understand objections from religious groups because scripture would still be offered.

At Warners Bay, construction was expected to begin yesterday on the $30,000 project and needs to be completed in two weeks.

Scripture teacher Kate Robertson said religious education was a popular program among year seven students.

"This course is a values-based program that encourages students to understand their own sense of worth and discover a life of purpose," Ms Robertson said.