AUSTRALIANS will get the chance to have their say on same-sex marriage with the High Court ruling the Government can spend $122 million of taxpayers’ money on a controversial postal survey.

Ballots with the question, “Should the law be changed to allow same-sex couples to marry?” will be sent to households across the nation on September 12.

If a majority of people vote in favour, a vote will then be held in parliament which the Prime Minister Malcolm Turnbull says he expects will make same-sex marriage legal. If Australians vote no, Mr Turnbull has said the parliamentary vote will not proceed.

Campaigns by both the yes and no campaigns are now set to crank up following the decision with TV, newspapers and the internet set to be flooded with ads from both sides.

The Government funded the multi-million survey using laws which allowed the spending if there was an urgent need and the situation was unforeseen.

Same-sex marriage advocates had argued the survey was neither urgent nor unforeseen and the Government could not spend the funds without parliamentary approval, which it would be unlikely to get.

But the High Court ruled that was not the case, effectively giving the green light to the poll.

Mr Turnbull was convinced the postal vote wouldn’t be stopped by the court.

“Our advice has been such that we’re confident the action we’re taking is not going to be stopped or injuncted by the High Court,” he said

“Australia’s parliament is where decisions about laws are taken and if we take one group of people and say your rights have to go through a tougher process before you get to Parliament that’s an unfair process,” he said.

But with the tick having been given to the survey it was full steam ahead, Mr Brady said.

“We’re in it to win it. We know that the Australian people are for [SSM] and we’ll do everything we can to ensure those values reflected in the result,” he said.

It emerged on Thursday that $14.1 million dollars had already been spent on the survey for an advertising campaign encouraging Australian to check their details on the electoral roll and on printing the ballot papers and envelopes.

In late August, the Australian Electoral Commission said 90,000 people had joined the electoral roll ahead of the same-sex marriage postal vote with almost a million Australians checking their details.

Unlike usual votes, the postal survey is voluntary. Forms need to be returned by early November but yes campaigners have predicted 80 per cent of forms could be sent back by the end of next week.