Fuel duty was therefore set to rise by 3.02ppl on January 1, 2012, and then again by inflation on August 1, 2012.

However, in last year’s Autumn Statement, the chancellor delayed the January rise to August 1 and cancelled the original August 1 rise – expected to be 1.92ppl.

Then, in June this year, he announced that the 3.02ppl rise would again be delayed until January 1, 2013.

Edmund King, the AA’s president, said: “Recent political focus has been on the 3.02ppl fuel duty increase, scheduled for January 1, either ignoring or unaware that unrestrained wholesale prices have been running rampant in the fuel market.

The Government momentarily had a grip of this when the previous transport secretary called in the industry to agree wholesale price transparency.

“This initiative stalled when the Office of Fair Trading called for information on road fuel pricing – to which the industry has responded by pumping up wholesale prices and then not passing on cost savings in a timely fashion.”

The AA is now able to match movements of UK wholesale fuel prices against price movements at the pump.

Regionally, price reductions have favoured the north and the Midlands, with most areas enjoying cuts over the past month of at least 2ppl. In East Anglia and the south, the cut has ranged from 1.2p to 1.8ppl.

On average, the cheapest diesel is sold in Yorkshire and Humberside (141ppl) and the most expensive in Northen Ireland (142.6ppl).

• For detailed regional fuel prices, click here