The average price of a litre of petrol and diesel at UK filling stations rose by 4p and 4.7p respectively during February, according to RAC data.
The motoring organisation said these rises represented the biggest monthly increases seen for five months.
It said the hikes had been driven by by the price of oil breaking through the $80 a barrel mark on 8 February and staying there for the rest of the month.
RAC spokesman Simon Williams said: “What’s especially galling is the continuing difference in price between Northern Ireland and the rest of the UK. On average fuel is 5p cheaper there, with big retailers appearing happy to operate on thinner margins per litre.
“Looking at average margins across the whole of the UK, retailers are currently taking around 10p a litre on average across both petrol and diesel. The supermarkets in particular have now noticeably upped their margins to 8p a litre compared to 6p in 2019. Luckily for drivers, this is lower than the last two years when it was around 9.5p.
“When analysing the supermarkets’ prices via the Competition and Markets Authority open data scheme, it is also very clear there are some big differences between the cheapest and most expensive prices charged for both petrol and diesel. Frighteningly, at the end of February there was an 18p difference between the country’s cheapest supermarket unleaded and the dearest, and for diesel it was 21p.
“We hope that the eventual introduction of the monitoring body recommended by the Competition and Markets Authority will help to bring an end to this postcode lottery that treats drivers so unfairly.”
