Proponents for same-sex marriage say the vote, which is being challenged in the High Court and whose outcome is not legally binding, exposes gays and lesbians to a bruising campaign for no good reason.
If you haven't already, you must be enrolled to vote in Australia to take part in the postal plebiscite.
Many local celebrities have come out in support of the yes campaign, and on Wednesday night Ellen DeGeneres tweeted her support, urging Australians to enrol and update their electoral details ahead of the August 24 deadline.
But earlier this week, Coalition MP Warren Entsch said: "If it comes back no, I reserve my right as a Liberal to call on a vote".
A sex worker is offering a big discount for those who are voting yes in Australia's survey on same-sex marriage.
Meghan Trainor has slammed an Australian anti-marriage equality ad for using her picture without her permission. We apologise to Megan Trainor and her support base if this has caused any angst or distress.
Australia Post workers are fearing for their safety in the lead up to the same-sex marriage plebiscite.
The Thor: Ragnarok star utilized Instagram on Wednesday to call for all "open minded, free speaking, laid back, life loving" Aussies to do not forget to enroll and update their electoral details so they can vote YES on marriage equality. I encourage everyone to participate and if you don't agree with it, participate.
The poll offers residents the chance to get involved in lawmakers' decision on whether or not to legalise same-sex marriage, although it does not hold any mandatory bearing on politicians.
Ahead of the vote there has been a surge in homophobic hate speech in the country, with leaflets distributed in Sydney bearing the slogan "stop the fags" and linking gay people to "child predators".