Soaring world oil prices have already wiped out the 1p fuel duty cut announced in the Budget, according to latest figures from the RAC.
It said the average UK price of petrol is now 133.55p a litre, which is 0.02p higher than the average price on March 23 when the duty cut was announced.
The average price of unleaded in Northern Ireland on Friday was 133.83p per litre, the steepest in the UK. On March 18, the average price here was 133.8p per litre.
Diesel here was 139.7p per litre on the same date, while on Friday the average was 140.09.
RAC motoring strategist Adrian Tink said: “The volatile oil market has meant that drivers have seen very little benefit from the duty cut. Prices are continuing to spiral upwards with no end in sight to the high prices.
“The Chancellor made a great deal about the ‘Fair Fuel Stabiliser' but it's only stabilising government revenue.
“And just to add to the pain, the delayed inflationary increase of 3.02p is due to come in on January 1. Who knows what the price of fuel will be at this point?”
The AA said that the UK average for diesel was now 140.13p a litre — within 0.13p of the record set on March 23.