The Government is being accused of taxing all motorists to pay for roads that will benefit only some areas.
Legislation passed under urgency in Parliament means petrol tax will increase by 3 cents a litre every year for the next three years. The first increase will come into effect on 1 July.
The Government intends to put the money raised into its National Land Transport Fund.
New Zealand First MP Andrew Williams says it's not fair that the whole country has to pay for a small number of roads - most of which will benefit people north of Hamilton.
However Transport Minister Gerry Brownlee says the National Land Transport Fund takes care of a large number of roading projects around the country.