Victoria's Public Transport Minister has made a pitch in Canberra for $4.5 billion in federal funding for the Melbourne Metro Rail Project, but is flying home without a cheque.

Jacinta Allan pressed the state's case for Commonwealth cash in a meeting with federal ministers in the capital today, in the hope they will agree to match the Andrews Government's contribution to the $11 billion public transport project.

Victoria would seek the remaining $1.9 billion from the private sector.

Ms Allan said the meeting set up the next stage of negotiations with the Turnbull Government about an equal funding partnership, ahead of the state and federal budgets in May.

"Today wasn't necessarily about leaving with a cheque in hand, as nice as that would have been," she said.

"Today was very much about talking through the detail of the project, but setting up the next stage of discussions that need to be undertaken before we go to that final issue of funding."

Asked if the project would proceed without federal funding, Ms Allan said the Andrews Government was "absolutely committed to delivering the Melbourne Metro Rail Project".

The proposed route for the Victorian Government's Metro Rail Project. ( Supplied: Victorian Government )

Federal Major Projects Minister Paul Fletcher and Infrastructure and Transport Minister Darren Chester described the meeting as a productive first step.

Mr Fletcher said the Federal Government would wait until Infrastructure Australia had assessed the business case and provided advice before deciding whether to chip in.

"We really need to receive that advice before we can take any decisions on whether Melbourne Metro would be funded by the Commonwealth Government and if so, when that would occur, what amount, and of course what form that funding might take," he said.

"Would it be a grant, would it be a loan, would it potentially even be equity."

The Government last week released the revised business case for the project, which involves twin 9-kilometre tunnels connecting South Kensington and South Yarra and five new underground stations.

A cost-benefit analysis showed the project would generate a return of $1.10 for every dollar invested, or $1.50 if wider economic benefits were included.

But Victoria's Opposition Leader Matthew Guy said Labor could not be trusted to stick to the project's budget.

"This project is just a barebones $10.9 billion and it's bound to blow out," he said.

"As soon as it blows out beyond $400 to $500 million it's going to blow the business case."

The State Government has ruled out a hike in public transport fares to help pay for the project.