Thousands of people have rallied in Brisbane for same-sex marriage, with several streets in the city blocked off for the event at Queens Gardens in the CBD.
Queensland unions, entertainer Dolly Diamond, and Dykes on Bikes were some of those who addressed to the crowd.
The High Court upheld the legal validity of the non-binding postal survey last week, with a vote result expected in mid-November.
Australian households will begin receiving postal surveys this week.
About 10 protesters at today's Brisbane rally held up placards and shouted slogans denouncing same-sex marriage.
Convenors of the Queensland YES campaign urged the crowd to push for a "strong, positive and respectful" argument in favour of same-sex marriage. Director of the YES campaign, Peter Black, said he was excited by the "energy" and "enthusiasm" of the crowd.
"It's clear the values of equality and a fair go are really resonating with Australians," Mr Black said.
But Mr Black urged caution in light of recent polling.
"We can't be complacent, we can't take anything for granted," he said.
"Today we'll be encouraging our supporters and our community members to engage in a series of respectful conversations with their friends, family members, colleagues, to explain why marriage equality matters to them and why this is a reform that people should get behind."
Ms Diamond, who is originally from the UK and now lives in Melbourne, said at the Brisbane rally that Australia was "dragging their feet on marriage equality" compared with other countries.
For four years I've been an Australian citizen, and very proud of that — wouldn't want that to change in any way, but the Liberal Government needs to sort this out," she said.
"They're sorting this out with a postal vote — not my way to sort it out — but we'll fight it and win it with YES because we need equality.
"We're being asked a very, very simple question — do you believe in same sex marriage, yes or no?
"I believe it's yes, and I believe the majority of Australians believe exactly the same."
Steve Rushbrook said he was at the rally today in Brisbane to show his disbelief that Australia still does not have marriage equality.
"It is disgraceful that it's come to a public vote of others having to approve or disapprove of how or who we're going to love — it's just unbelievable, ridiculous," Mr Rushbrook said.
In Sydney, Prime Minister Malcolm Turnbull urged Australians to vote yes and said he failed to see how it would threaten the institution of marriage.
Speaking at the NSW Liberals and Nationals for YES campaign launch in Sydney, Mr Turnbull said the question facing the nation was one of fairness.
