The state government has revealed Queensland's largest infrastructure project will open later and cost more than previously planned.
Brisbane's Cross River Rail will now cost $6.3 billion, with Transport Minister Mark Bailey on Friday revealing a blow-out of $960 million.
The underground heavy rail network will now open to the public three months later than expected, in the first quarter of 2026.
Mr Bailey said an extra $848 million is required to deal with rising costs, while a further $112 million has been allocated to acquire additional land at Roma Street.
"This is absolutely unavoidable; the economic headwinds are very strong," Mr Bailey said.
The state government has stressed Cross River Rail was still the "best managed" mega project in the country.
"That [increased] figure comes in at just under a billion dollars, when you look at Sydney, the Sydney Metro is over by $6 billion," Mr Bailey said.
"It's unavoidable to have impacts from the COVID pandemic, from La Niña, the Ukraine war, supply chain impacts.
"We've been very careful to do this using external advice, so it's done forensically."
Cross River Rail is a 10.2 kilometre rail line from Dutton Park to Bowen Hills, which includes 5.9 km of twin tunnels under the Brisbane River and the CBD.
Underground track installation has been completed along all sections of Cross River Rail's twin tunnels.
The project was initially budgeted to cost a total of $5.4 billion.
