The Tasmanian Liberal Party has voted to support traditional marriage at its state conference in Launceston, Saturday.
The motion, preserving the current legal definition of marriage as being between a man and a woman, was passed by a majority of the delegates, a move being praised as "a positive affirmation" of the importance of marriage to communities.
"The Tasmanian Liberal delegates have shown leadership and courage in what has often been a vicious debate," the Australian Christian Lobby's Tasmania Director, Mark Brown, said.
"Marriage between a man and a woman has been an undisputed party policy for both major parties for decades and its definition has only in recent years been questioned due to the prolonged campaigns by the same-sex marriage lobby," Mr Brown continued.
"[It] is a vital institution for the stability and cohesion of society and it shouldn't be redefined for anyone."
Gay marriage supporters have also responded to the decision, denouncing the Council's stance as a "shameful" step backwards.
"At a time when countries like the UK and the US are moving forward on marriage equality it is shameful that the Tasmanian Liberal Party wants to take us backwards," director of Australian Marriage Equality, Rodney Croome, said.
Australian Senator and Greens party leader, Christine Milne, also criticised the move as discrimination against gay couples.
"They want to take us back to discrimination...and as far away as possible from equal opportunity," Senator Milne said following the result.
Last month, former Australian Prime Minister Julia Gillard conceded that it was only a 'matter of time' before same-sex marriage would be legalised in the country, while a recent Crosby/Textor survey revealed that public support for marriage equality was at a 72% high.