Victorian Premier Daniel Andrews is urging Prime Minister Malcolm Turnbull not to go ahead with a plebiscite on same-sex marriage, saying it will be expensive and hurtful.
Australians will take to the polls later this year in a compulsory yes-no vote on whether to change the Marriage Act.
Tony Abbott put the plan for the referendum through, before Malcolm Turnbull took over as Liberal Party leader.
Daniel Andrews reminded Mr Turnbull of the botched republic referendum, after which Mr Turnbull a pro-republic leader, attacked Prime Minister John Howard for breaking the nation's heart.
The premier said if Mr Turnbull fumbles this crucial moment, history will remember him for the same thing.
Australian correspondent Steven Price told Mike Hosking the process is costing $160 million.
"This is going to get very nasty, it's going to turn very ugly - I think it's a good thing that Australian people are going to have a say on this, but it's going to be a very drawn out and extensive exercise."
LISTEN ABOVE: Australian correspondent Steve Price speaks with Mike Hosking