Premier Denis Napthine has moved to bolster the Coalition's public transport credentials before the November 29 election, with a promise to build a long-awaited rail link to Melbourne Airport.

Addressing a gathering of Liberal Party faithful, Dr Napthine confirmed the May 6 state budget would include plans for a new electrified rail service running along dedicated tracks from Melbourne Airport to Albion, where it would join an existing rail corridor running to Southern Cross Station.

Under the plan, the service would leave Southern Cross Station every 10 minutes during peak periods, with the journey expected to take about 25 minutes.

''This project has been on the books for over 40 years and a Napthine Coalition government will outline our plans to build this rail link in the upcoming state budget,'' Dr Napthine told the Liberal Party state council.