Motorists have been warned that the price of diesel will hit a record high this weekend in a fresh squeeze on living standards.

The surge in the oil price to over $100 a barrel since the start of the Iran war has driven up the cost of filling up on forecourts across Britain.

Figures from the RAC show the average price of a litre of diesel is now 198.32p – up 14.5p this month alone and 55p since the conflict began at the end of February.

It now costs £109 to fill up a typical 55-litre family car with diesel – £30 more than before the war broke out in February.

The cost of petrol has also soared, with unleaded now averaging 173.6p a litre, its highest price in four years.

Experts have warned of worse to come, with diesel on the verge of reaching the previous record high of 199.09p.

This was set in June 2022 after Russia invaded Ukraine, sparking a similar economic shockwave and inflation shock.

Hundreds of forecourts are already charging £2 a litre for diesel as the Iran war hits motorists in the pocket. 

RAC head of policy Simon Williams said: ‘The average price of diesel is teetering on the brink of a new all-time high.

‘The record of 199.09p will almost certainly be surpassed over the weekend as retailers continue to pass on the increases they're seeing when they buy new supply.’

The latest surge in prices at the pumps came after oil rose back above $108 a barrel on Thursday, having started the year at around $60.

Petrol prices have risen by 12p a litre this month and more than 40p a litre since the Iran war began – pushing up the cost of a typical tank of unleaded by £22 to £95.

‘Sadly for drivers, there appears to be no end in sight to high prices at the pumps,’ said Mr Williams. ‘A significant drop in the price of oil is badly needed but this seems unlikely without the US and Iran striking a deal.’

Surging fuel prices, caused by the effective closure of the Strait of Hormuz due to the war and global oil supplies being squeezed, have been one of the drivers of rising inflation in the UK, which now stands at 3.1 per cent and is set to rise above 4 per cent early next year.

It will pile pressure on Labour to abandon plans for a Fuel Duty hike in next month’s Budget, the first of Andy Burnham’s premiership.

At present, Fuel Duty is set to be hiked by 3p a litre on January 1 and a further 2p on March 1, netting billions of pounds more for the Treasury as it scrambles for cash to pay for a series of unfunded commitments made by Mr Burnham during his first weeks in Downing Street.

But the hike would come just as household energy bills are expected to rise, further squeezing hard-pressed families.

Experts also point out that diesel is the backbone fuel of the haulage sector, meaning higher diesel costs are passed on and push up the price of goods on shop and supermarket shelves.