Tasmanians United for Marriage Equality convener Andrew Badcock said he was disappointed ``but it doesn't mean that this is a matter exclusively for the federal government''.

Advocates say the Tasmanian same-sex marriage bill is drafted differently from   the ACT's and does not draw upon the federal definition of marriage, which was what doomed the ACT legislation.

Murchison Independent MLC Ruth Forrest moved a motion unsuccessfully in October to bring back the bill to the Tasmanian upper house. 

Ms Forrest said the decision by the High Court was as expected and consistent with advice received from Brett Walker, QC, earlier in the year.

``My reading of it is that it still leaves room for state-based law if legislation is framed correctly,'' Ms Forrest said.

She said her heart went out to those who had married under the  ACT laws.

Australian Marriage Equality national director Rodney Croome said the decision gave hope to his cause. 

``The decision confirms that the federal government does have the power to legislate on same-sex marriage,'' Mr Croome said.

Save Marriage Coalition spokesman and Liberal candidate for Lyons Guy Barnett said he hoped the Legislative Council would reject any further push for same-sex marriage laws in Tasmania.

``I believe this vindicates their decision. With the matter now definitively decided by the High Court, the Tasmanian government and same-sex marriage advocates must stop peddling their social agenda and focus on issues like the economy and jobs,'' he  said.