Increased supermarket profit margins led to drivers paying an extra 6p per litre for fuel last year, an investigation has found.
Watchdog the Competition and Markets Authority (CMA) said average supermarket fuel margins rose by 6p per litre between 2019 and 2022.
The inquiry also found that an increase in margins on diesel across all fuel retailers cost drivers an extra 13p per litre during the first five months of this year.
