It will cost about $5.4 billion to build a much-needed second river rail crossing in Brisbane to ease traffic congestion, Queensland’s deputy premier says.
Jackie Trad revealed on Sunday the government had received the project's business case "in the last 72 hours".
When asked whether it gave a better insight into how much the project, previously estimated to be $5.2 billion, would cost, Ms Trad replied: "The cost of this project is in the vicinity of $5.4 billion.
"We have always said that this is a significant project."
She said Building Queensland would review the business before it went to cabinet for final consideration.
Ms Trad welcomed federal Labor announcing on Sunday it would, if elected, contribute $800 million to the project.
It comes after the state government set aside $50 million in its budget last week to establish a delivery authority to oversee final planning and delivery.
It means federal Labor's commitment still leaves the project $4.55 billion short.
"We have always said that a project of this scale and size will require a variety of funding sources," Ms Trad said.
"Federal government assistance, state government assistance, local government assistance, but also private sector assistance."
Ms Trad had previously flagged businesses and residents in Brisbane's CBD possibly being taxed more to help pay for the project, which would increase their property values.
The business case's summary would be made public, she said.
"There will be information in the public domain, but please understand the government has just only received the business case and we will be ensuring that it gets the due deliberation it's entitled through the cabinet process," she said.
Ms Trad said it was too early to say what the funding split would be between the three tiers of government.
Shadow Treasurer Scott Emerson said a "massive $4 billion question" remained over Cross River Rail.
"Who's going to pay for this project?" he said.
"Even with (Opposition Leader) Bill Shorten's election bribe of $800 million, it has a big asterisk against it - only if the business case stacks up."
Cross River Rail, the state's highest priority infrastructure project, will see 10.2km of track laid, and 5.9km of tunnel under the Brisbane River and CBD