Unless a High Court challenge stops it, Australians will soon vote on same-sex marriage - by post.
The Coalition government has said repeatedly it would offer Australians a plebiscite on the issue.
Unlike a referendum, which needs a majority of votes to pass, a plebiscite does not oblige the government to enact its result.
But as the government's second attempt to hold a plebiscite was also voted down in parliament, the public is now likely be offered a postal ballot.
The Prime Minister says if there's a majority 'yes' outcome, he will hold a free vote in parliament on whether the law should be changed.
Referendums and plebiscites are usually held to change the constitution, and the High Court has previously stated constitutional change is not necessary to change the Marriage Act.
The Howard government changed the Marriage Act to specifically exclude same-sex marriages in 2004.
Australian National University demographer Dr Liz Allen doesn't have a high opinion of a postal ballot as a method.
She says not only is it inaccurate, but highly exclusionary, and means some community groups and sectors of society won't get to have their say.
"If everyone's opinion was truly wanted, a different methodology would be adopted. In fact if you are looking for the least-likely-to-succeed methodology, this is it. We have a very unique geography in Australia. We have quite remote locations, primarily Indigenous locations. We're also a highly multicultural country, we have linguistic differences. Now these are just some of the characteristics about Australia that make it difficult for such a survey of the population to gather a representative sample of information."
Dr Allen says the "postal" nature of the ballot affects people who are overseas, those without a fixed address or who choose not to have their details listed on the electoral roll.
The Labor member for Lingiari in the Northern Territory, Warren Snowdon, says Australians in remote parts of the country face additional barriers to participation.
"Most Aboriginal people who live in remote communities don't have a mailbox, so there's the issue of how they actually get mail in the first place, how they post mail, how regularly the mail arrives, and what their capacity is to access the mail. There are a large number of people who are not on the (electoral) roll, and in addition, there's the issue of language, where a large proportion of people who live remotely have English as a second or third language as the literacy skills are very difficult, who would potentially not be able to read or write. These people will not get the opportunity to be informed properly, and I don't think many of them will get the opportunity to vote."
Migrant communities and people from non-English-speaking backgrounds may also be at a disadvantage.
Founder of the Asian Australian Alliance, Erin Chew, says many in these groups don't understand the issue of same-sex marriage, let alone how to vote on it.
"Particularly from the Asian community, a lot of them still hold quite conservative or traditional views as to what marriage is, and a lot of that is due to the fact that they don't know much about what same-sex marriage entails. A lot of them probably won't even know what a plebiscite is, or they won't understand the purposes of why this has gone to a postal vote. A lot of the more complex or complicated issues around that is even beyond them, and again, as I said, that comes because it's so rushed, it's as though they just want this to be over and done with without thinking that a huge percentage of Australians won't have enough information to make the most rational or the best decision possible."
Unlike a referendum, voting in the postal poll is voluntary, causing additional concerns.
Among them, that parts of society could view the issue of same-sex marriage as not relevant to them.
Acting Chair of the Federation of Ethnic Communities' Councils of Australia, Eugenia Grammatikakis, says it's vital that every Australian is encouraged to have their opinion heard.
"Irrespective of what individuals believe around this particular issue, what is important is that information is out there, they are informed about the issue and about the process and should they wish to exercise the right to vote then they know how to do that, where to go and who to approach."
