Melbourne Port sale monopoly faces reviews

The Port of Melbourne's new owners will face regular reviews of whether they have misused their monopoly power.

If they refuse to play by the rules, the Victorian government will have the power to terminate the 50-year lease.

The Essential Services Commission will be in charge of the reviews, after concerns from the Australian Competition and Consumer Commission about the $6 billion port lease.

Treasurer Tim Pallas said the ACCC had acknowledged the new measures were "significant progress" towards ensuring the new port owners did not abuse their monopoly power to drive up rents.

"The safeguards that we're putting in place, the strongest safeguards in Australia with regards to any port lease arrangement, are now going to be augmented and even further strengthened," Mr Pallas told reporters on Wednesday.

The port's agreed future capacity - and trigger points that would allow the state to build a new port without paying compensation - will also be released publicly once the deal is signed.

Mr Pallas said the port's capacity was likely to be about 7.5 million containers a year, down from the eight million Labor predicted before the state election.

In the ACCC's submission to a parliamentary inquiry into the port sale, it argued proposed five-yearly ESC reviews were not enough to stop monopoly abuses.

"By this time, harm resulting from the exercise of substantial market power will already have occurred and may not be possible to be undone," the submission said.

Mr Pallas said the new safeguards would make sure costs would be kept down at the port to protect the economy.

Victorian Greens leader Greg Barber said minor changes to the deal wouldn't protect exporters from increased costs.

"The government wants maximum sale price for their re-election war chest, but that's going to come at the expense of our export competitiveness," he said.

Victorian shadow treasurer Michael O'Brien says the port sale has become a "dog's breakfast".

"This is a huge embarrassment, and all the backflips in the world, all the last minute policy on the run changes can't hide that basic fact," he said in a statement.

"Selling off the port as a 50-70 year monopoly is just bad for Victorians and will cost jobs."