The Prime Minister has pledged up to $5 billion to help build the long-awaited rail link from Melbourne’s airport to its CBD.

A Melbourne airport train line has been debated and planned for decades, but Malcolm Turnbull has declared his funding promise will ensure it becomes a reality.

“The time for talk is over. There have been countless reviews, reports and recommendations but Melbourne is still waiting for a service almost all of the world’s great cities take for granted,” Mr Turnbull said.

“This is the rail link that Melbourne, Victoria and the millions of people who use the airport every year demand and deserve.”

Congestion has been steadily worsening in Melbourne, and the Prime Minister said building the link would “slash travel times, bust congestion, boost the Victorian economy and create thousands of new jobs.”

While the funding announcement is significant, the $5 billion pledged will not be enough to cover the entire cost of the project.

Mr Turnbull will today ratchet up pressure on the Victorian Government to make a matching commitment and pour in another $5 billion.

“We are under no illusion that such a city-shaping project does not come cheap. That is why we are making such a significant commitment,” Mr Turnbull said.

“We want the Victorian Government to partner with us in a true 50:50 funding partnership to build and own this iconic piece of infrastructure. We also welcome the involvement of the private sector.”

Last year, the Victorian Andrews Government announced it wanted to build an airport rail link within a decade.

As part of that plan it also wanted to boost services to Geelong and the country, as well as “untangle” the current rail network.

The Victorian Government argues that would maximise the benefits of the link and ensure it did not simply become an “expensive funnel” between the airport and CBD.

The Federal Government has not committed to that idea, but it has not yet ruled it out either.

The Coalition has already committed $30 million to put together a business case for the rail line – and Mr Turnbull said that would provide a clearer picture of the best route, as well as the project’s final price tag.

The Victorian Liberal leader Matthew Guy was quick to pounce on the announcement.

“$5 billion! If the Andrews Govt won’t build an airport rail link, it’s outstanding to see the federal Liberal National government will,” he said on Twitter.

-ABC