Since peaking at 143.04p a litre on 5 May last year, the pump price of diesel fell back to 137.59p in July before starting to climb again. Two years ago, diesel in the UK averaged 113.62p a litre.

For a commercial van with an 80-litre fuel tank, the cost of filling up has risen from £90.90 in February 2010 to £ 114.44 now, having dropped to £110.07 in July.

Over the same period, the average price of petrol was 112.03p a litre two years ago and set a new record of 137.43p on 5 May 2011. Since then, it fell to 132.25p per litre at the turn of the New Year before starting the climb to the latest average of 135.39 p.

'A stronger pound has staved off this moment for longer than might have been expected, but diesel drivers across the country will have been watching in trepidation. They hoped that below-record prices would hold until the spring, when winter price pressures on diesel traditionally ease,' said Edmund King, the AA’s president.

'However, the impact of record diesel prices will be felt by everyone as higher transport costs are passed on to business and consumers. With some delivery and haulage firms adding a diesel surcharge to invoices, costs will rise faster than most people expect and stoke inflation again.

'Like petrol, there is no price transparency in the wholesale and retail diesel market. Although the diesel price has been influenced by refinery closures, unreliable supply into Europe and stock market speculators taking advantage of a tight market, there is no way for businesses and consumers to find out whether or not they are paying a fair price.'

Mr King added: 'It is galling to see Brent crude shoot up from around $112 a barrel earlier this month to nearly $120 now, despite the International Energy Agency’s lower forecasts for oil consumption in 2012. With trouble in the Middle East one of the causes, the pattern of oil pricing is looking to mirror last year’s – once again inflated by stock market speculation.

'The difference is that, from last year’s experience, we know the consumer can’t take it,' Edmund King concluded.

The AA has written to the Chancellor calling for an investigation of the oil, refining, fuel product and retail markets to ensure UK families and business are protected from over-inflated prices and supply difficulties.  

It has also called for an end to annual fuel duty hikes while the economy falters. This includes cancelling the planned rise in August.