24/09/2017 3:37 PM AEST | Updated 24/09/2017 3:44 PM AEST

Social Media A 'Once In A Lifetime' Tool For Marriage Equality Supporters

#postboxselfie encourages Aussies to get out and vote.

Some of the #postboxselfie team, Lee Kiraga, Alan Arazo, Katherine Allan and Tim Callow.

A group of 'Yes' supporters are harnessing the power of social media to motivate Australians to cast their vote in the same-sex marriage postal survey.

The #postboxselfie campaign encourages voters to photograph the moment they post their survey response and share it on social media with the #postboxselfie hashtag.

"As this survey isn't compulsory, the goal is to encourage 'Yes' voters to go to the post box and post their vote, so that it counts," founder Lee Kiraga told HuffPost Australia.

"The concept of #postboxselfie is to make it fun, and to share your 'Yes' vote with your friends and family online.

"(It's) a once in a lifetime opportunity to merge 1900s technology, 21st century trends and our fight for civil rights."

He said the group decided to use social media as it enabled them to reach a wider audience than by using traditional campaign methods like door-knocking.

Social media was especially effective at reaching young Australians who, despite overwhelmingly supporting marriage equality, were sometimes reluctant to cast a vote, Kiraga said.

"It meant that they'd have to find a post box to take their selfie, then upload it and share it, so it's about distribution and exposure too," he said.

The #postboxselfie volunteers, who call themselves "people who want equality and love to win", were pleased with the positive response to their efforts so far.

The campaign has almost 300 submissions to its Instagram account since launching on September 13, according to Kiraga.

"I've had some messages telling me the page has meant a lot to them as it's provided them with positivity and hope," he added.

The innovative campaign signals how popular social media has become with Australians, including Prime Minister Malcolm Turnbull, as a platform to express their view on marriage equality.

It also represents a less controversial example of marriage equality activists using technology to push their case after the 'Yes' campaign sent unsolicited text messages urging support for gay marriage to voters over the weekend.

With campaigning in full swing, an undisclosed number of people received an SMS encouraging them to vote 'Yes', sending social media into meltdown and causing invasion of privacy concerns for some recipients.

The Turnbull Government decided on the $122 million postal vote as a way to determine if the definition of marriage should be changed to include same-sex couples. Labor and the Greens wanted a free vote in parliament on the long-running issue.

Since commencing earlier this month doubts have been raised over the validity of the survey's result after numerous reports of forms being damaged, stolen or destroyed.