A vote on legalising same-sex marriage in Australia will proceed after a court dismissed two legal challenges.
The non-binding survey to gauge support for changing Australia’s Marriage Act is due to begin next week.
The High Court of Australia dismissed separate objections by same-sex marriage advocates, who had argued the postal vote was invalid.
The survey does not have the power to make same-sex marriage legal, but it could lead to a vote in parliament.
Prime Minister Malcolm Turnbull has said the law could change this year if the vote shows majority support.
“We encourage every Australian to vote in this survey, to have their say,” he said on Thursday.
The voluntary survey has drawn controversy over its A$122m (£75m; $97m) cost and fears that it will prompt hate-filled campaigns.
Australians will have from Tuesday until 27 October to cast their vote. The results are expected to be announced on 15 November.