Event organiser Margaret Hughes said she represented a small group concerned about the injustice of Australian marriage laws.

"I believe they [politicians] need to hear what the community is saying," Ms Hughes said.

"It is about them making a choice, whether they listen or not, and that means putting aside their own assumptions and world views," she said.

However, Save Marriage Coalition spokesman Guy Barnett said it was time for people to move on as the topic had been "comprehensively debated" and "defeated" in both federal and state Parliament.

"Most Tasmanians are telling me that the economy is, and should be, a priority for our government and that we should move on from same-sex marriage," Mr Barnett said.

Speaking to the crowd, Tasmanian gay rights campaigner Rodney Croome said he remained confident that people would soon be able to marry their partner of the same sex and encouraged people to use September's federal election to show their support.

"In the next few weeks we will see couples marrying in Britain, marrying in France, in New Zealand ... and when that happens, more and more Australians will ask, "why not us'," Mr Croome said.

"We can make this happen, we don't have to be left behind - if ordinary Australians stand up and be heard in support for equality for all Australians that will make the politicians listen."