The long-running bid to lease Melbourne's port for $6 billion now has a "rock hard deadline" of Thursday.
If the government and opposition can't agree on legislation by then, Treasurer Tim Pallas says he will sell the 50-year port lease using the State Owned Enterprise Act.
"Thursday is a rock hard deadline, and we will not be wavering in our commitment," Mr Pallas told reporters on Monday.
"We are now of the view that the opposition intend never to pass this bill. They keep talking positively to the media, they keep avoiding a hard negotiation with us."
The port sale has been delayed as the government and opposition fight over what compensation should be paid if a competing port is built before Melbourne reaches capacity.
The opposition has suggested 15 years of compensation, while the government has come down from 50 to 30 years.
Mr Pallas said selling the port lease directly would bring in more money than if the government accepted the opposition's compensation amendments.
"We have crawled on our hands and knees to get the opposition to a point where they can see that the interest of the taxpayer, the community, are best served (by this deal)," Mr Pallas said.
Opposition leader Matthew Guy said the government has been ducking attempts to make a deal - he says he's not had a meeting or phone call about the port from Mr Pallas or Premier Daniel Andrews.
Mr Guy said the government's latest 30-year position was deliberately too complex to disguise its intent.
"Which is to get a 50-year compensatory regime, which is, as the industry will tell you, far too long," Mr Guy told reporters.
If a deal is done on legislation the port could be on the market within nine months - selling it without parliament's approval could take up to 15 months.
Mr Pallas said Greens leader Greg Barber was implacably opposed to the sale.
"I could crawl, I could adopt whatever positions the laws of nature would allow me to adopt, but I can pretty certainly tell you that I still wouldn't change (the Greens) view," Mr Pallas said.
Shadow treasurer Michael O'Brien later said selling the port without legislation would leave the buyer open to competition-law challenges, because a buyer won't have legal backing from the parliament.
The government planned to sell the port's lease to pay for infrastructure upgrades, including removing suburban level crossings.
