More than two-thirds of Australians have cast their votes in the same-sex marriage postal survey.
The Australian Bureau of Statistics received 10.8 million forms (or 67.5 per cent) by Friday, up from 10 million the previous week.
Equality Campaign executive director Tiernan Brady is confident the majority of Australians will back changing the Marriage Act.
"I think we've confidently won the argument," he told Sky News on Tuesday.
Mr Brady said opponents of same-sex marriage had spent weeks trying to shift the marriage debate onto other topics.
"They've talked about everything apart from marriage equality and I think the Australian people have seen through it," he said.
Australia's support for same-sex marriage had hovered between 60 and 65 per cent for the past five years, and Mr Brady hopeful the figure will be reflected in the postal survey results.
"I think the public have made their mind up," he said.
The survey closes on November 7 and the results will be released on November 15.
