Hundreds of millions of dollars will be spent to run trains through Melbourne's long-awaited second rail tunnel.
Victorians got their first sneak peek into the 2025/26 state budget on Monday, with Premier Jacinta Allan announcing it would contain an extra $727 million for the $15 billion Metro Tunnel.
The cash injection will go towards switching on the twin 9km tunnels later in 2025 and delivering turn-up-and-go services for the Sunbury, Cranbourne and Pakenham lines.
Metro Tunnel was originally costed at $10.9 billion when announced in the 2016 budget.
The price tag for taxpayers has grown to $13.48 billion and the total project cost beyond $15 billion after an $837 million blowout was confirmed in September.
But the premier insists the extra $727 million in funding does not amount to another cost overrun as it is for service delivery.
"We've made the capital investment ... to get to the point where we can now in this year's budget fund the services," she told reporters on Monday.
A further $98.7 million will be set aside to deliver more frequent services for passengers on other lines under a "public transport blitz" worth almost $5 billion.
Major construction on new underground stations for Metro Tunnel has been completed at Parkville, Arden and Anzac.
With Town Hall or State Library stations unfinished, the government remains tight-lipped on an exact opening date.
Opposition public transport spokesman Matthew Guy labelled the Metro Tunnel cash splash "government spin".
"For that money we could have built two brand-new hospitals ... we probably could have built around three dozen schools," he said.
"But instead the government boasts about switching on infrastructure."
Ms Allan also spruiked her government bringing forward $2 billion to redevelop Sunshine Station as part of the first stage of building a rail line from the city to Melbourne Airport.
In 2018, the state and federal governments promised $5 billion each to build the link, which at the time was expected to cost between $8 billion and $13 billion.
Victoria pushed back its completion date until at least 2033 in the last state budget amid a dispute with Melbourne Airport over station design.
The airport backed down following the intervention of an independent mediator, with Prime Minister Anthony Albanese earmarking an extra $2 billion in federal funding to get the wheels turning on the project again.
Jaclyn Symes will hand down her first budget as Victorian treasurer on May 20 after replacing Tim Pallas, who retired in December after 10 years managing the state's books.
She has ordered an independent review into the Victorian public service as the government looks to cut up to 3000 jobs to curb its rising wage bill.
Victoria's net debt is on track to hit $187.8 billion by mid-2028, pushing up interest expenses to $9.4 billion annually.
