The Federal Government has signalled for the first time that it could be willing to commit funds to Melbourne's multi-billion-dollar Metro Rail Project.

The State Government is yet to secure any federal funding for its $11 billion Melbourne Metro Rail tunnel, which includes five new underground stations at Arden, Parkville, CBD North, CBD South and Domain, connected by two tunnels.

Former prime minister Tony Abbott had said $3 billion of federal money earmarked for the Napthine government's scrapped East West Link road would remain in a "locked box" and could not be used for the rail project.

But Mr Turnbull has signalled a significant shift in the Commonwealth's reluctance to fund urban rail projects, pledging to assess Labor's project on its merits.

"We will look at it very carefully, and with a very open mind," he said.

Cities and the Built Environment Minister Jamie Briggs went a step further, saying the Federal Government would "find a way" to fund the project.

"Clearly it's part of the solution, it's undeniable," he told 774 ABC Melbourne.

He added: "The Melbourne train system is at capacity ... and it needs to work well for Melbourne to work well."

Construction for the rail project is due to begin in 2018. ( Supplied: Victorian Government )

Mr Briggs said he was waiting on a business case from Victoria before committing any funds to the project.

"When that work is done we'll engage with the Victorian Government about what it is that the Commonwealth can do to help make that happen," he said.

Mr Briggs conceded Mr Abbott's announcement that he would not be funding the Metro Rail project was a "communications mistake".

Premier Daniel Andrews, speaking from a tour of China, said he was encouraged by the Turnbull Government's position.

"It's a very significant thing for the new Prime Minister to have jettisoned, to have got rid of this ridiculous policy that prohibited the Federal Government from putting even one dollar into better public transport," he said

Mr Andrews said he expected to hold more talks with the Federal Government when he returned from a trade mission to China.