Victoria's Premier Denis Napthine has pledged to build a rail link between Melbourne and the city's airport at Tullamarine.

Speaking to delegates at the Liberal State Council, Dr Napthine said the Coalition's plans would be outlined in the upcoming Victorian budget.

"This project has been on the books for over 40 years. Thirty million passengers a year use Melbourne Airport and that is expected to double in the next 20 years," he said.

"Our airport rail link will provide high capacity, efficient service on a regular basis to Melbourne Airport.

"It is time that this rail link was built and it will be built by a Coalition Government here in Victoria."

With a state election due in November, Dr Napthine said his Government could be trusted to deliver the key piece of infrastructure.

He said Victorians have "a real choice" when they cast their vote.

"Do they vote for a Labor Party that has a history of the desalination disaster, of the Myki mess that we had to fix, of the North-South Pipeline white elephant?

"Do they vote for a Labor Party that are puppets of the union bosses who are taking money and taking instructions from the CFMEU leadership?

"Or do they vote for the Coalition, which has a real vision to build a better Victoria... and stronger local communities?

"A Coalition Government that has plans to build the regional rail link, has plans for our port capacity, has plans for East West Link and has plans for a Melbourne Airport rail link?

"Our Government has the vision, we have the runs on the board."

But Deputy Opposition Leader James Merlino said the Liberal Party has made similar promises before.

"Denis Napthine and the Liberal Party promised rail links to Avalon, to Doncaster, to Rowville. None of them have been delivered," he said.

A study conducted by Public Transport Victoria last year suggested the best option for a rail service between the airport and the CBD would be the Albion East route.

This would connect with the proposed metro tunnel at Footscray and the journey would take about 30 minutes.