The wholesale price of petrol has risen by over 1.3ppl since the start of this week, making the RAC’s claims that prices of £1 per litre will be commonplace by Christmas increasingly unlikely.

This was the message from the PRA, which said the supermarkets cutting their prices to 99.9ppl for petrol today defied the reality of the market.

PRA chairman Brian Madderson said the struggling supermarket groups, desperate to draw shoppers away from Aldi and Lidl, were treating fuel as a loss leader.

He said: “This action defies commercial reality in an increasingly volatile market and leaves the independent forecourt retailers having to explain to motorists why their pump prices are not falling in the same manner.

“If and when the wholesale price of petrol does fall – and it is higher now than it was in mid-November – then the UK will see a reduction to average pump prices which are still stubbornly sitting at above 106ppl.

“It remains increasingly unlikely that motoring organisations’ strident wishes for £1.00 per litre across the UK will be seen in 2015.”

Speaking on Sky News, he said that oil prices would need to remain at below $40 a barrel for a sustained period, and the sterling to dollar exchange rate would need to remain stable or move in sterling’s favour, before any real falls in the wholesale price, and following that the average pump price, could be expected.