A tiny town in New South Wales has become an unlikely same-sex marriage battleground, after Australia Post ordered a rainbow flag be removed from one of its outlets.

David Wilson, who is the post office licensee in Cobargo, hoisted the flag on Wednesday morning.

But it was not fluttering for long — Mr Wilson spoke to ABC Radio to discuss his decision to fly the flag but a short time later, he was told to take it down.

"We believe we are a well-respected and accepted part of the community in Cobargo and it's important that we're a little bit more visible at this time," he said.

"People realise when people take this vote of yes or no, it's not just a whimsical two-second opinion poll, for people like us it's our life, it's our future.

"My partner of nine years, [it means] whether we can get married or not.

"We work there together in the post office. We've never had any issues in Cobargo, it's a very accepting and lovely town."

With a national postal survey looming on the issue later this year, most votes of Cobargo's 800 residents will likely pass through Mr Wilson's shop.

In a statement, Australia Post said: "While we acknowledge that our employees and other representatives are entitled to their individual views, as a government business enterprise Australia Post needs to ensure its post offices and other facilities are not used for making statements on political issues."

Mr Wilson has moved the flag to private property, adjacent to the post office.

It is not the first time the pride flag has caused controversy in government buildings.

In February, Tasmanian senator Eric Abetz complained in an estimates hearing about a rainbow flag in the foyer of the Department of Finance's Canberra headquarters.