Legal bids to block the Federal government's same-sex marriage postal survey have flopped.
The High Court's thrown out challenges to the $122 million survey, not accepting the argument of it being unconstitutional.
The survey forms will now be mailed out from next Tuesday.
The Prime Minister was informed of the ruling in parliament.
"Every Australian will have their say and that is as it should be and we encourage every Australia to vote in this survey, to have their say."
One of the main figures in the failed legal action was Tasmanian Independent MP Andrew Wilkie, a heavy critic of the survey, favouring a vote by members in parliament to sort it out.
He's now rallying up Australians to take part and vote yes.
"The challenge now is to get a high turnout and to get a strong yes vote and then the challenge will be for Malcolm Turnbull to respond to that, do as he's promised and to get a bill into the parliament and get it voted on quick smart."