The Australian Christian Lobby (ACL) is urging supporters to petition the Labor Party against changing its policy on marriage at its National Conference next month and has produced a video featuring “prominent Australians” to support it.

The ACL enlisted former Nationals leader John Anderson in the video to lobby Labor. The only Labor politician willing to take part was Tasmanian senator Helen Polley.

“Having been in public life for a long time I think there are certainly limits to the ways in which the state should interfere in people’s private lives,” Anderson said.

“However, I think it’s critical that the state stand up for those that are too young to speak for themselves.”

Polley said she had been married for 35 years and that marriage was “the cornerstone of our society” and where children learned about morality.

“With all the discussion and debate over the issue of marriage and the definition, I’ve heard no arguments from the community to want to change my view on why it is so important that we keep marriage as what it is currently,” Polley said.

Also appearing in the video were Shop, Distributive and Allied Employees Association national secretary Joe de Bruyn, Sydney Anglican Archbishop Peter Jensen, and pastors Darlene and Mark Zschech of Hope Unlimited Church.

The ACL has called on members to sign the petition following its own national conference, where de Bruyn said Labor was under intense pressure for change.

“Mr de Bruyn said that the only hope of stopping such a change is to demonstrate that it would be electoral suicide to do so,” the ACL website said.

The petition so far has around 35,000 signatures and the ACL is hoping for 100,000 signatures by the end of November.

A GetUp! petition in support of marriage equality has been signed by more than 76,000 people.