Newshub understands new Labour leader Jacinda Ardern is about to hit Aucklanders with a regional fuel tax.

The money raised would be used to transform the city's creaking transport infrastructure and help pay for light rail from the CBD to Auckland airport.

Transport in Auckland is an on-going issue, with gridlock and delays causing frustration. But Ms Ardern is set to unveil an infrastructure plan for the city on Sunday.

"People can guesstimate about what that might be," she says.

Funding for that plan will come at least in part from a regional fuel tax on motorists.

"People want to know that when we promise to deliver something, we've got a plan to do it."

One of the promises expected on Sunday is to fast-track a light rail service from Auckland's CBD to the airport, with an estimated cost of between $1 and $1.5 billion.

It could be built within five years - much sooner than the Government's plan of a bus corridor then rail within 30 years.

But Transport Minister Simon Bridges says there's no need to fast-track the project because another's just been completed.

"Waterview, which is having a transformational impact on that route to the CBD - we've halved travel time and it's more reliable."

The details will be revealed on Sunday, but what's clear now is that Labour is heading in a very different direction on transport - big, bold promises, and a plan for motorists pick up the tab.

Newshub.