Premier Chris Minns has not ruled out major changes to Australia's biggest public transport project after revealing more cost blowouts for the Sydney Metro.
The Minns government has been inspecting the state's books since taking office, and claims the former Coalition government hid the true cost and timeline for several stages of the driverless train network.
The premier today announced an independent review would examine the delivery models, cost overruns, and the final price tag to be paid upon completion.
Internal government documents seen by the ABC show the City and Southwest Metro project is set to cost $20.11 billion, but the "publicly announced" figure under the Coalition was $18.5 billion.
The government has also flagged a cost blowout of the Sydney Metro West line, which will link the CBD with Parramatta.
It was meant to cost about $18 billion, but internal documents show it will now exceed $25 billion.
Mr Minns could not rule out changing or removing stations on the Sydney Metro West project after discovering the cost had risen by $6 billion.
"I think common sense dictates that in order to make sure that we don't make the same mistakes twice, we've got experts in the room to make sure the taxpayers of this state know we are getting value for money," he said.
He said work on both projects, which has commenced, would not be delayed or stopped while the review was underway.
The ABC understands the previously secret price tag may still not build a fully functioning metro, and the final touches could add another billion dollars.
The new premier said it was undeniable the projects were "in trouble and need rescuing", but wanted to move forward rather than dwell on past decisions.
"I'm not interested in casting blame or putting on a show trial in relation to the previous government," he said.
The review will be led by former Commonwealth head of infrastructure Mike Mrdak, and assisted by former Queensland Transport and Main Roads department director-general Amanda Yeates.
Transport Minister Jo Haylen said she needed to find "solutions" to overspending issues.
"Every day, we are asking more about the Sydney Metro and discovering more key details the former government did not reveal to the public," she said.
"We are being up-front and honest about the challenges we are inheriting."
The City and Southwest Metro project will convert the T3 Bankstown line to a metro, with services leaving every four minutes in each direction between Bankstown and Sydenham.
It will link to a new line under the harbour between Chatswood and Sydenham, with stations to be built at sites such as Barangaroo, Pitt Street and Waterloo.
The internal documents show the former government had already budgeted for $20.5 billion.
A business case for the City and Southwest Metro, published in 2016, estimated the project would cost around $12 billion.
But the government announced in the 2022-23 budget that construction costs and the pandemic had pushed it to $18.5 billion.
Ms Haylen hinted that project may be delayed as the administration comes to terms with the budget situation.
During the election campaign, Labor warned it a would take a more conservative approach to spending on some infrastructure projects announced under its predecessor.
Two further Metro sections — one linking Bankstown to Glenfield and the other linking Parramatta to the new airport line — will be put on the backburner under Labor.