Retailers would be “incredibly stupid” to display prices for half a litre if diesel reaches £1 a litre, says the AA Motoring Trust.

Because the majority of pole signs are not able to display more than 99.9ppl, retailers are being forced to consider their options, as fears of diesel breaching £1 a litre continue to grow.

But the current favoured solution – displaying prices for a half litre – has been slammed by the AA.

A spokesperson for the AA Motoring Trust said: “Motorists would be absolutely floored if pole signs displayed prices for half a litre – it’s likely to rouse suspicion among motorists.

“They will drive up to the forecourt, not understand the price and drive off. I think there would be a very strong backlash from motorists; I wouldn’t want to be the person standing behind the till.”

Instead of the half-litre price solution, the AA wants retailers to put a number one in front of existing numbers to keep some consistency for the motorist, but the spokesperson added: “Retailers will need to keep a close eye on their signs in case the number one stickers get washed off or blown away.”

Mark Bradshaw, chief executive of GarageWatch, said: “Someone needs to give some thought to this – it’s an awful situation to be in. Maybe in some cases people will be able to turn the middle panel upsidedown so the decimal point is in the right place, but in the interim period, we’ll have to display prices for half a litre.”

Record crude prices and a lack of refinery capacity have been blamed for the hike in diesel prices, and supplies are likely to be squeezed further during the winter, as demand for diesel as a heating fuel increases.