UK fuel prices went up by around 2p per litre in December, according to the RAC.
It says the average cost of a litre of diesel went up from 117.72p to 120p, while the average petrol price went from 114.39p to 116.46p.
The RAC says it blames supermarkets raising their fuel prices above the increase seen on the wholesale market, and claims the cost of filling up should really be 118p per litre for diesel, and 113p for petrol.
RAC fuel spokesman Simon Williams said: “It’s very disappointing to see some of our biggest fuel retailers putting up their prices over and above the increases seen on the wholesale market. There’s a definite feeling that they have been trying to protect themselves for what was to come in terms of further coronavirus restrictions.
“While wholesale prices went up very slightly in December our data shows there should be scope to lower forecourt prices rather than put them up. Retailers will no doubt argue that the pandemic is leading to drivers filling up far less so their ‘per litre’ profits are considerably down, and Monday’s announcement of another lockdown will be treated as justification for their decision not to pass savings on at the pumps.
“Unfortunately, those who still need to fill up regularly are having to pay more than they should be as, by our calculations, both fuels should actually come down by 3p a litre in the next fortnight.”
Williams did say however that the oil market was still being adversely affected by Covid-19 travel restrictions, meaning that fuel prices might still be lower than they would otherwise be.
He added: “As and when life begins to become more normal as a result of the Covid vaccination programme the price we pay for fuel will inevitably go back up again.
“A year ago, a litre of unleaded set drivers back 127p and diesel 132p, which is 10p and 12p more expensive, respectively, than today.”