Major project building costs have blown out by $11.7 billion, as an embattled state government tries to sully the integrity of its independent financial auditor.
The total estimated investment (TEI) of 113 projects ballooned by 8.7 per cent in a year, based on the annual review of infrastructure spending by the Victorian Auditor-General Office.
It takes the total price tag to $145.5 billion.
Tabled in state parliament on Wednesday, the review monitors the costs of projects valued at $100 million or more against their set budgets and timelines.
Forecast costs of 53 projects jumped by $14.9 billion in total, 25 fell by $3.3 billion, 32 did not change and three had no estimate.
The balance comes to an overspend of almost $11.7 billion.
Of the 10 projects most closely scrutinised, five had significant price estimate changes of 20 per cent or more at some point in their life cycle.
"(It) suggests that cost estimation is not always reliable at business case or investment decision stages," Auditor-General Andrew Greaves wrote in the report.
"Entities' cost estimation and cost planning capabilities are also not adequately identifying construction market price volatility."
Transport Infrastructure Minister Gabrielle Williams took a blowtorch to the report, claiming the calculations were "wrong" and methodology "shoddy".
"They've failed, and they should be accountable for that," she told reporters at state parliament.
The minister suggested the body had not properly factored in scoping changes on projects but was unable to provide an alternative figure.
"I'm not going to enter into a tit for tat on figures," she said.
AAP has put the claims to the auditor-general's office.
It's not the first time the state Labor government has attacked integrity agencies during its decade in power.
Premier Daniel Andrews repeatedly refused to apologise and rejected former ombudsman Deborah Glass's finding his government breached human rights by suddenly locking down Melbourne public housing residents in 2020 during the COVID-19 pandemic.
When the Independent Broad-based Anti-corruption Commission ruled a Labor-affiliated union was unfairly awarded a $1.2 million contract, Mr Andrews branded the report "educational" - drawing further criticism from the watchdog's then-boss Robert Redlich.
Victoria's major project pipeline has been plagued by budget overruns and delays, including on the North East Link, West Gate Tunnel, Metro Tunnel and Airport Rail.
Premier Jacinta Allan and her government must stop making excuses and start taking responsibility for their shocking track record, Opposition Leader Brad Battin said.
"This chaos cannot continue," he said.
The $34.5 billion first stage of the Suburban Rail Loop, a planned 90km orbital train line to run from Melbourne's outer southeast to outer west via the airport, is undergoing a "pricing reset" with its early works contractor, Wednesday's report revealed.
It is to factor in items that were unknown or uncertain when the contract was signed, including ground conditions, hazards and contamination at some sites such as properties that were not properly inspected due to access restrictions.
That work had not be finalised before the expected deadline of June 2024, risking further delays.
Tunnel boring on the $26 billion North East Link toll road project is suspended because of a sinkhole.
The $13.48 billion Metro Tunnel should open later in 2025, but technology to allow commuters to touch on and off with their bank cards or any smartphone won't be ready in time.
Myki ticket readers across the tunnel's five new stations will be ripped out and replaced when the state updates the system.
The cost of replacing the old readers is within a $1.7 billion contract awarded to New Jersey-based company Conduent to overhaul and operate the system for the next 15 years, Ms Williams said.
