The Australian Bureau of Statistics gay marriage law postal survey form is seen in a residential letterbox in this September 16, 2017 illustration image. REUTERS/Jason Reed/illustration

SYDNEY (Reuters) - Around 12.6 million Australians, or 78.5 percent of eligible voters, have voted so far in a postal ballot on whether same-sex marriage should be legalized, the Bureau of Statistics said on Tuesday.

The poll, which closes later on Tuesday, is non-binding, but the government has said it will put a proposal to parliament to make Australia the 25th nation to permit same-sex marriage, if a majority of voters are in favor of it.

The final results will be announced on Nov. 15.