Same sex marriage could be legalised in a matter of days if the matter was to be decided in parliament, opposition spokeswoman Tanya Plibersek said .
The High Court will consider its ruling on the several challenges to the Federal government's $122 same-sex marriage postal ballot this week, but Ms Plibersek says the vote should have been made in parliament.
"There are private members bills on the books now, we could have marriage equality through in a mater of days if the government just allowed the parliament to do its job," she told reporters in Sydney on Sunday.
"This $122 million postal vote is a waste of money."
The opposition education spokeswoman says the debate has already hurt same-sex couples and families across the nation.
"We've already seen the debate take a very nasty turn and we've said all along that this will be damaging and divisive and pretty hard on a lot of people," she said.
The voluntary survey was Plan B after the Senate blocked the compulsory plebiscite.
If it is found unconstitutional in the High Court, Prime Minister Malcolm Turnbull will face a choice of doing nothing further on same-sex marriage this term, allowing a private member's bill to go to parliament or having another shot at passing the plebiscite bill.
However, he has repeatedly promised not to change marriage laws without the Australian people having a say.
