Opposition Leader Bill Shorten has slammed a new TV advertisement by opponents of same-sex marriage as "total rubbish" licensed by Prime Minister Malcolm Turnbull. The Coalition for Marriage's debut TV ad, which aired on commercial networks on Tuesday night, links marriage equality to sex education at schools. It claims that in countries which have legalised same-sex marriage, "parents have lost their rights to choose", and features an unidentified woman who says her son was told "he could wear a dress" to school.

The ad, which has been uploaded to YouTube and was authorised by Sophie York of the Marriage Alliance, does not directly address the question of whether same-sex couples should be able to marry. But it features another unidentified woman who claims: "When same-sex marriage passes as law overseas, this type of [school] program becomes widespread and compulsory."

Mr Shorten, who opposed the postal survey and its plebiscite predecessor, told Fairfax Media the ad was "offensive and hurtful to LGBTI Australians and their families".

"This is exactly what was predicted when Malcolm Turnbull decided to waste $122 million on a postal survey. He gave the green light to this rubbish," Mr Shorten said. "This is not freedom of speech. This is freedom to hurt. I just want to tell LGBTI families that they are not on their own. Most people know this is total rubbish."