A HISTORIC motion backing same-sex marriage has been passed by the Tasmanian House of Assembly.

It is the first time an Australian parliament has voted in favor of marriage equality for gay and lesbian couples, The Mercury reports.

The Greens motion also called on the Federal Government to change the Marriage Act.

Debate on the motion was watched by local and interstate same-sex marriage activists in the public gallery and by a large national audience on the parliament's internet broadcast.

The Labor Party backed the motion while the Liberal Party voted against it.

The historic moves comes 14 years after sodomy was decriminalised in Tasmania.

For more on this story, go to The Mercury.