For Brisbane mother Shelley Argent, the reason for Australia to legalize same-sex marriage is quite clear.

“I have two sons, one straight and one gay,” Argent told NBC News. “I want them to both have the same rights, responsibilities and privileges as each other. They are both loved equally, both pay taxes and contribute to society equally with their careers and talents. Fair is fair.”

Argent is one of the more than 16 million Australians who will be sent a postal survey on Tuesday that asks just one question: “Should the law be changed to allow same-sex couples to marry?” Results will be announced Nov. 15, but lawmakers are not bound to accept the outcome.

It’s a question many gay marriage advocates wanted Parliament to decide on its own, without putting the country through what is essentially a public vote on the issue. Critics of the postal survey say a non-binding public vote that could cost the government 122 million Australian dollars ($97 million) is unnecessary. They also fear such a vote will inflict an unnecessary trauma on Australia’s LGBTQ community, whom they now believe are being put in the position of having to defend the validity of their relationships to a voting public.

But after two challenges to the constitutionality of the postal survey were rejected by Australia’s highest court last week — paving the way for the postal survey to go ahead as scheduled — advocates for same-sex marriage are now ready to spend the next few weeks campaigning hard to ensure Australians answer the postal survey with a resounding "yes" vote.

“The decision by the high court was very disappointing,” Argent said," but it doesn’t mean we give up.” Read more via NBC