Labor leader Bill Shorten says it's important Australia isn't one of the last developed nations to legalise same-sex marriage, as the debate continues to divide the community.
Activists on both sides of the debate took part in events across the country at the weekend, with launches for the Yes and No campaigns.
Mr Shorten told reporters on Sunday the postal survey was on marriage equality, adding that "everything else is just white noise" as he continued his campaign for the Yes vote.
"All the other issues can be dealt with elsewhere," he said.
Senator Corey Bernardi launched the No campaign in Sydney on Saturday evening, telling an audience of 1000 a Yes vote would lead to "weaponised" anti-discrimination laws and "legal warfare".
"Vote no" appeared in skywriting over Sydney city on Sunday morning, and appears to have been funded by an anonymous Go Fund Me page which raised more than $2,300.
High-profile Yes campaigners, including Magda Szubanski and Sydney City councillor Christine Forster, attended rallies across capital cities on Sunday urging supporters to remember returning their survey forms.
Almost half of all eligible Australians should have received their ballot by the end of last week after survey forms were posted from September 12.
Results are expected on November 15.
