Fuel duty will rise more slowly than previously planned, Chancellor Alistair Darling said in his Budget speech.
A previously announced 3 pence rise in fuel duty will now be staggered, with a 1p rise in April, a further 1p rise in October, and then again next January.
"This staging will ease the pressure on businesses and family incomes," said Mr Darling.
Phasing in the increase rather than raising fuel duty by 3p immediately will cost £550m.
"The decision to phase in fuel duty is the second most expensive measure Mr Darling announced, and a difficult one for the Conservatives to reverse," according to BBC economics editor Stephanie Flanders.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.