The government will introduce legislation that makes it illegal to vilify, intimidate or threaten harm against people on the basis of them being LGBTI or having religious convictions, as part of its same-sex marriage postal survey.
But "yes" campaigners have warned that the method of collecting votes, via the postal system, could be less effective at engaging younger tech-savvy Australians, who are seen as more supportive of changing the laws.
However, several lawmakers have warned they will vote against such a law - irrespective of public opinion.
Some 1,400 voters were surveyed between Wednesday and Saturday last week for the poll.
While Football Federation Australia announced its support for gay marriage two years ago, the hugely-popular National Rugby League was a more recent advocate with chief executive Todd Greenberg only going public at the weekend.More news: Active shooter situation reported at New Hampshire hospital
We support marriage equality and believe all Australians deserve the freedom to marry the person they love, and to have their relationships recognised with the same dignity and legal protections as their neighbours, friends, and family.
The bill still requires approval from parliament before it can be put into action.
An Australian-initiated survey in 2015, with respondents mostly from Australia, Britain, Canada, Ireland, New Zealand and the United States, showed discrimination and homophobia remained widespread in sport.
She complains that "no" campaigners have compared children in same-sex relationship families to Australia's so-called Stolen Generations, mixed-race children who were taken from Aboriginal mothers under now discredited government policies aimed at raising them as non-indigenous Australians. The traditional marriage camp point to a short-lived online petition demanding that a Sydney doctor be deregistered for appearing in a television advertisement opposing same-sex marriage. The discrimination complaint has since been dropped.
After more than a decade of political wrangling, a national survey on whether gay marriage should be legalised got underway Tuesday with ballot papers mailed out.