During the spring statement on Wednesday, Chancellor Rishi Sunak announced a 5p cut to fuel duty, in response to rising prices at forecourts.
It will come into force at 6pm and remain in place until March 2023.
ITV News Consumer Editor, Chris Choi explains why we are unlikely to see an immediate change in prices at the pumps:
This looks like being one of the hot topics of the day.
The bad news according to my research is that it could take 10 days for some forecourts to reduce prices in line with any cut in fuel duty.
The way the industry works is that retailers are liable for the fuel duty as their stock is delivered.
So until their storage tanks are depleted they wont get fuel at that lower price and are unlikely to charge that lower price.
It's why the Petrol Retailers Association wrote to the chancellor asking him to build in a delay to the introduction of the new rate, giving them a chance to use up old stock.
Busy urban forecourts and supermarkets are likely to get through old stock quickly and cut prices in a day or so - but some rural outlets could take 10 days.