Australia’s highest court on Tuesday began hearing legal challenges against a national vote on same-sex marriage.
The government plans to hold a non-binding postal survey from next week to gauge support for changing the Australian law to allow same-sex marriage.
Prime Minister Malcolm Turnbull has said the vote could lead to the tabling of a bill in Parliament later this year, the BBC reported.
Intense campaigning has already begun, but the survey will not go ahead if the legal challenges are successful.
Two separate challenges by same-sex marriage advocates will be heard in the High Court of Australia on Tuesday and Wednesday.
Legal experts believe the court will rule on the matter quickly because the government is planning to mail out surveys from September 12, the BBC said.
The vote has drawn controversy over its $97 million cost and fears that it will prompt hate-filled campaigns.
Many same-sex marriage supporters want Parliament alone to debate legalising same-sex marriage.
Both legal challenges argue that the vote is invalid because its funding was not allocated through a normal parliamentary process.
The government unlocked the $97 million-fund for the survey through an act allowing it to pay for initiatives determined to be “urgent and unforeseen”.
The challenges said changing the Marriage Act does not count as an urgent matter, and the vote was not unforeseen because the idea was first publicly discussed in March, the BBC added.