The RAC has blasted the 'big four' supermarkets for failing to slash the price of fuel last month, which has helped keep pump prices higher than they should be.
It said the average price of petrol and diesel fell by 6p-a-litre in November - but reductions at the country's forecourts should have been at least twice that.
With the wholesale price of both fuel falling, petrol and diesel should have been 14p and 15p-a-litre lower than what they currently cost.
It said the failure of Asda, Morrisons, Tesco and Sainsbury's to cut their pump prices has seen retailers enjoy profit margins of more than 20p for every litre, which the motoring group described as a 'scandal'. 
'Blame the supermarkets!' The RAC has accused the big four of failing to pass on full savings of cheaper wholesale petrol and diesel, keeping UK average pump prices 'artificially high'.

Motoring group says petrol and diesel should be 14p and 15p-a-litre cheaper than they are
Unleaded fell from 165.96p at the start of November to end the month at 159.88p, whereas diesel dropped from 190.31p to 183.87p, the RAC said.
This saved motorists more than £3 a tank by the end of the month, it adds.
But driver should have pocketed far more substantial savings at the pumps, meu objectives the motoring group says.
RELATED ARTICLES Share this article Share 89 shares HOW THIS IS MONEY CAN HELP It says drivers lost out as the wholesale price of both fuels plummeted in November - but retailers failed to pass on these savings.
Wholesale petrol dropped by 11p from 122.63p to 111.53p and diesel decreased by even more, coming down 15p from 143p to 128p. 
Taking an average of wholesale prices for the last week of November, the RAC believes petrol should really be at an average of 146p and diesel to 169p - 14p and 15p lower than the current averages.
Consequently, it believes retailers are now collectively enjoying margins of more than 20p on each litre pumped into vehicles - a figure the RAC says drivers will 'find truly shocking as they struggle to put fuel in their cars to go about their daily lives'.
Unleaded fell from 165.96p at the start of November to end the month at 159.88p, whereas diesel dropped from 190.31p to 183.87p, the RAC said
!function(){"use strict";window.addEventListener("message",(function(e){if(void 0!==e.data["datawrapper-height"]){var t=document.querySelectorAll("iframe");for(var a in e.data["datawrapper-height"])for(var r=0;rThe motoring organisation pointed the finger at the big four supermarkets for failing to trigger price cuts across the sector.
A litre of unleaded bought at a supermarket cost 158.31p in November - down 6p in the month - which is only 1.6p lower than the UK average. 
Supermarket diesel at the end of November was down 3.7p to 182.74p, only a penny below the average price across the country. 
Historical data held by the RAC data shows that both fuels are typically 3.5p cheaper when bought at a supermarket.
RAC fuel price spokesman Simon Williams says this is sadly not the case this year, with major supermarkets accused of 'hanging on to massive margins for dear life'
RAC fuel spokesman Simon Williams said: 'It's bordering on a scandal that drivers are being overcharged so much because the big four supermarkets, which dominate UK fuel retailing, are flatly refusing to reduce their prices by bigger amounts.