But the Queensland government insisted there was absolutely no delay in the project.

A commercial-in-confidence market sounding materials report from August 2017, seen by Brisbane Times, says the Rail, Integration and Systems contract was due to be awarded in October 2018.

However, Cross River Rail chief executive Graeme Newton last week told the Australian Financial Review the project's three major contracts would be awarded in the first half of 2019.

The RIS contract is responsible for connecting Cross River Rail into the existing Queensland Rail network.

The August 2017 report, developed by the Cross River Rail Delivery Authority, provided "proposed timeframes for key activities for the primary works packages with a focus on the procurement phase and early delivery phase", apparently given to industry as indicative dates.

"These dates are subject to refinement," the report said.

LNP deputy leader Tim Mander said the government was "failing miserably" to deliver what it had promised.

"This puts serious doubt on this Labor government's ability to deliver their pet project by 2024, as stated in their own business case," Mr Mander said.

"When it comes to major infrastructure projects, Labor have a track record of budget blow-outs, delays and costing taxpayers millions of dollars in the process."

However, a spokeswoman for Treasurer Jackie Trad said the RIS contract had not been delayed.

"Formal bids will be assessed by the Cross River Rail Delivery Authority in a formal assessment process and a recommendation made to the government in the first part of 2019 for its consideration," she said.

The spokeswoman said the three major contracts - the $634 million European Train Control System; RIS alliance; and the Tunnel, Stations and Development public-private partnership - would be awarded throughout the first half of 2019, and locked in by mid-2019.

Asked if that meant the awarding of the RIS contract was eight months delayed, the spokeswoman said: "No."

Asked if this meant the expected completion date of 2024 for Cross River Rail was in doubt, the spokeswoman said: "No."

Cross River Rail's total cost of $5.4 billion had also not changed, she said.

Two consortia have been shortlisted for the RIS alliance contract:

Cross River Rail is a 10.2-kilometre rail line between Dutton Park and Bowen Hills, which includes 5.9 kilometres of tunnel under the Brisbane River and CBD.

It will include four new underground stations at Boggo Road, Woolloongabba, Albert Street and Roma Street, as well as upgrades for the Dutton Park station and Exhibition station.

In June 2017, the Queensland government committed to fully funding Cross River Rail.

It was first announced by the Beattie Labor government more than a decade ago, in March 2007.