Anti-gay-marriage groups have slammed comments by Labor and the Greens linking a national vote on same-sex marriage to the deadly Orlando mass shooting.
Opposition Leader Bill Shorten backed away from associating a plebiscite with gay hate crime on Saturday, after earlier making reference to the mass killing, but he said he was concerned "ugly arguments" would emerge.
But the Greens say there's "no question" the murder of 49 people at a gay nightclub proved hateful views persisted in the community.
Greens leader Richard Di Natale used "vile" online comments in response to the Orlando attack as evidence those attitudes were shared by some Australians.
"A plebiscite will unleash those voices of hate in the community," he told reporters in Sydney on Saturday.
"And we give those views legitimacy by endorsing a plebiscite."
It's a view the Greens had held consistently since the national vote was announced, he said.
The opposition leader raised eyebrows during an online debate with Prime Minister Malcolm Turnbull when he linked the Orlando shooting to hate campaigns that could accompany a plebiscite.
The Australian Christian Lobby - which strongly opposes gay marriage - hit back, labelling Mr Shorten's comments "extreme emotional manipulation".
"I am disappointed that aspiring political leaders would think about their fellow Australians this way," managing director Lyle Shelton told AAP on Saturday.
Those who believed in traditional marriage should not be described as "haters" or "extremists", he insisted, adding the nation had engaged in respectful debate on the issue for a decade.
Anti-gay-marriage group the Australian Marriage Forum believes Mr Shorten has insulted voters who have sincere concerns about redefining marriage.
"How dare Mr Shorten label decent Australians as haters and try to smear them with the actions of an Islamist mass-murderer in Orlando?" president David van Gend told AAP.
Mr Shorten wouldn't repeat the comparison on Saturday, saying Australia didn't face the same situation as the United States.
But he maintains children of gay parents should not be exposed to "taxpayer-funded nonsense" against same-sex marriage.
"I recognise that some of the critics of marriage equality have extreme views," he told reporters on the NSW Central Coast on Saturday.
Mr Shorten slammed the prime minister's commitment to a plebiscite, accusing him of being "too chicken" to vote with his heart in parliament.
"It is time that he started leading not following his party," he said.
That was echoed by Senator Di Natale, who urged the prime minister to ditch the "Tony Abbott view of the world" and bring on a vote in parliament.
Young people would suffer mental illness as a consequence of the plebiscite, he said.
Mr Turnbull on Friday brushed off the national vote as a decision made by his party before he was installed as leader, insisting the coalition kept its promises.
His party has pledged to hold the $160 million vote if returned to government on July 2.
Labor has vowed to put same-sex marriage to a vote in parliament within 100 days of being elected.
