Lawmakers in Tasmania have rejected a proposed bill which sought to legalize gay marriage in the Australian state.

The measure cleared the state's lower house of Parliament last month.

But members of the upper chamber, the Legislative Council, raised questions about the proposal's constitutionality last night. Eight of its 15 members signaled their opposition to the measure, though a final vote was delayed.

Marriage in Australia is regulated by the federal government. However, Labor Premier Lara Giddings had argued that states could enact such legislation because the marriages of gay and lesbian couples are currently not regulated by the government's Marriage Act.

Former state chief justice Bill Cox intervened on behalf of opponents, saying the legislation would likely be struck down in court.

“Any such legislation would create a minefield in respect of rights, and make Tasmania a legal laughing stock,” Cox is quoted as saying by the Brisbane Times. “It is foolish to enact legislation which has a strong chance of being declared invalid.”

Proponents said they would look to the states after federal lawmakers rejected a gay marriage bill earlier this month.

(Related: Australian Senate joins House in rejecting gay marriage bill.)