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. Sale pastor Heidi McIvor in the Coalition for Marriage's new television advertisement. Credit:YouTube / Coalition for Marriage 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." Bill Shorten approved an $11 million grant to the ACTU's training arm but it has only spent less than 25 per cent of it over five years. Credit:Justin McManus The Labor leader nonetheless encouraged Australians to participate in the postal survey and promised to "campaign hard" for a "yes" vote. The ad also drew criticism from the executive director of the Equality Campaign, Tiernan Brady, who labelled it "disgraceful and dishonest". "The people behind this ad know that the Australian people are for allowing all Australians the right to marry, so they have resorted to misleading people, to pretend this is about something else," he told Fairfax Media.

"Sadly, over the next few weeks, the Australian people will get used to this daily dose of red-herrings and lies, served up by a bucketful of cash. As the 'no' side seek to divide Australians, we will continue to seek to unite them." The Coalition for Marriage said the women featured in the advertisement were not actors but "real mums who are bravely speaking out about their concerns". It has since emerged that at least one of the mothers in the ad worked for Coalition MPs and Family First senator Steve Fielding. In a statement, Ms York said parents across Australia "are speaking to each other about the impacts of radical LGBTIQ sex and gender education programs". She said parents had "a right to know how a change in the marriage law will affect what their kids are taught at school" because "the education departments won't tell them".

On the ABC's Q&A on Monday night, Attorney-General George Brandis – a supporter of same-sex marriage – said any bill introduced under the Coalition would contain "very strong protections" for religious freedom. But he warned against obfuscation of the issue by opponents of same-sex marriage. "Let us remember what this plebiscite is about. It is about one question and one question only: should the law be changed to allow same-sex couples to marry," Senator Brandis said. Loading "That's it, that is the only question the Australian people are being asked to decide."

Coalition for Marriage spokeswoman Monica Doumit said she was unsurprised by Labor's response to the ad because the party wished to "punish and silence those who disagree" with its position on same-sex marriage.