Auckland motorists will be paying the new 10 cents a litre regional fuel tax by mid-next year.
The government has confirmed that the tax revenue requested by the Auckland Council to help with transport funding will be in place by 1 July.
The Minister of Transport, Phil Twyford, said the necessary law change will be an early move.
"We'll make it a priority in the next few months to get that legislation passed," Mr Twyford told RNZ.
"The critical thing I know for Auckland Council is they are currently preparing their budget for their long term plan and they need some certainty around that."
The 1 July date would allow the Auckland council to drop its Interim Transport Levy of $114 per household - a three-year measure designed to boost transport funding ahead of new revenue.
Mr Twyford said the government was looking at a GPS-based road pricing system, but something like that could be decade away.
The Auckland Mayor Phil Goff will outline his proposals for the city's next 10-year budget on 30 November with the fuel tax being an important part of the revenue mix.