A motion calling for reform of the Marriage Act to allow gay marriage succeeded at state conference on Sunday.

Gay law reformists - who are hoping the issue will be brought up at the national ALP conference starting on Thursday in Sydney - have said the decision is timely.

However, a spokesman for Attorney-General Robert McClelland said the Federal Government's position remained clear.

"The Government has made it clear that it regards marriage as being between a man and a woman," he said.

"Couples who have a mutual commitment to a shared life should, however, be able to have their relationships recognised.

"The Australian Government supports the development of state and territory- based, nationally consistent scheme for the registration of committed adult relationships that are not marriages."

Braddon MHR Sid Sidebottom, Denison MHR Duncan Kerr and Lyons MHR Dick Adams believed the Government's policy would not be changed.

Bass MHR Jodie Campbell and Franklin MHR Julie Collins were unavailable for comment yesterday.

Cross-factional group Rainbow Labor has been lobbying national conference delegates to support gay marriage or civil unions. Group spokesman Matthew Loader yesterday said he expected there to be some change in regards to same-sex couples to the ALP platform this weekend.

"I expect that out of the conference there will be some changes to the platform to reflect that what is in there at present is offensive and insulting and inadequate," he said.

"Even if the conference doesn't get to same-sex marriage, which is possible, it may well, for instance, get to civil unions."

Tasmania, the ACT and Victoria already offer civil unions for same-sex couples.

Both Rainbow Labor and the Tasmanian Gay and Lesbians Group yesterday called for Premier David Bartlett to take the issue to the national conference.

Mr Bartlett said on ABC radio yesterday that gay marriage reform was not to be acted on by State Government.

State Attorney-General and Deputy Premier Lara Giddings said gay marriage was a federal issue and it was down to the Australian Government for same-sex marriage reform to happen.