Australia Coalition For Marriage

The organisation had a lead role in lobbying for the "No" case - associated with the Australian Marriage Law Postal Survey. Other organisations partnering with the Coalition for Marriage, in opposition to same-sex marriage, include the Australian Catholic Bishops' Conference, the Australian Christian Lobby and Marriage Alliance.

The first Coalition for Marriage advertisement on TV featured three women and focused on the Safe Schools education program. In the ad, the women – Heidi McIvor, Cella White, and Pansy Lai – ask about potential gender confusion issues for children. The ad was supported by Conservative senator Cory Bernardi and by social commentator Andrew Bolt. The ad was criticised as being inaccurate and for linking the survey (and same-sex marriage in general) to Safe Schools, and by Opposition Leader, Bill Shorten who said, "Malcolm Turnbull ... gave the green light to this rubbish". Mothers of transgender children criticised the ad for bringing their children into the same-sex marriage debate. The three women and supporters of the yes position have all commented on the responses to the ad. Minister for Environment and Energy Josh Frydenberg expressed that he "did not have a problem" with the advertisement, stating that he has "great confidence in the public's ability to make their own decisions as to whether they'll be voting yes or no".

One of the women in the ad (Dr Lai) was threatened that she would be shot “this week” and a campaign was initiated (subsequently pulled) to revoke her medical registration.

• Australian Catholic Bishops' Conference