A business case for a Gold Coast version of a Fast Train concept was revealed on Friday, plus very general plans to extend the heavy rail line to the Gold Coast Airport at Coolangatta.

On the Sunshine Coast, however, former prime minister Malcolm Turnbull had announced money in January 2018 for a business case for Fast Train concept to the Sunshine Coast, from Nambour to Brisbane.

“I am expecting the business case to come back in July,” Sunshine Coast federal MP Ted O’Brien said on Friday. “From there it goes to Infrastructure Australia.”

The federal election is expected to be held in May 2019.

Infrastructure Australia is the peak body prioritising infrastructure projects around Australia for additional federal funding.

The idea is to have trains run at 150kmh and travel between Brisbane and Nambour in 45 minutes.

The Sunshine Coast stretch alone of a Fast Train concept would cost “billions of dollars”, Mr O’Brien said.

The Sunshine Coast Fast Train bid is being prepared by a Sunshine Coast business consortium called North Coast Connect, which includes Stocklands – who are building the Aura residential development at Caloundra South – and engineers and planners SMEC, Urbis and KPMG.

The business case will work out where the Fast Train can work with the existing rail lines and where new rail lines for Fast Trains would be needed.

It will also identify a range of routes to Nambour and includes testing of the side rail line through the Aura residential complex to Maroochydore. This segment has been identified for three decades as the CAMCOS (Caboolture to Maroochydore) corridor study.

Mr O’Brien said he believed the Fast Train concept remains viable.

“While there will always be challenges, it remains viable,” he said.

Mr O’Brien said he was not yet in a position to reveal exact dollar amounts or track options, because that work was now being done by the business consortium.

“But I anticipate the business case identifying routes because ultimately it is based on those route options that the costings are done.

“So you are looking at using a mix of existing Sunshine Coast rail corridors as well as the CAMCOS corridors.”

A Queensland's Department of Transport and Main Roads spokesman confirmed the Sunshine Coast business case was still being evaluated.

"This means operational, technical, financial and environmental impacts of the project are yet to be determined," a departmental spokesman said.

"Any proposal for fast rail would need to complement the existing network, appropriately address future network requirements and include consideration of staging and integration with related network enhancements," he said.

"Rolling stock, resourcing and (train) stabling requirements are also critical."

On a separate rail project, the federal government has already promised to contribute $390 million to add a $780 million second rail line – duplicating the track – between Beerburrum and Landsborough.

The Queensland Government believes the federal government should contribute more than 50 per cent of the funds for this work.

However, this stretch of rail is within the Sunshine Coast Fast Train Brisbane to Nambour concept.

Federal Labor on Wednesday promised to set up a High Speed Rail Authority to evaluate the various high-speed-rail projects if it wins the May 2019 election.

Meanwhile, the Federal MP for the Gold Coast seat of Moncrieff, Karen Andrews, on Friday said people should not be sceptical about a Gold Coast Fast Train concept announced so close to a federal election in May.

That concept promises a trip between Brisbane and the Gold Coast in 35 minutes, but no planning has been done.

It follows work on the City Deal for South East Queensland, where fast train travel is key.

“What the Liberal National Government has committed to is to fund a business case; $8 million to fund a business case to look at fast rail between the Gold Coast and Brisbane,” Ms Andrews said.

“Also we are looking at extending the rail line south from Varsity Lakes through to the Gold Coast Airport.”