In its latest Fuel Price Report for May, the organisation reports that across the UK, the average pump price of petrol dipped back below 130p to reach 129.92p a litre – compared to 129.74p in mid April. Diesel, at 136.17p a litre in mid May, has barely budged from last month’s 136.26p a litre.

The AA adds that average UK petrol prices went back above 130p a litre at the end of April and continue to hover around that level. However, a war where supermarkets have pitted vouchers against rock-bottom pump prices still leaves the cheapest petrol in many big towns and cities at year lows of just under 126p.

In small rural towns where major supermarket competition is less fierce or only one supermarket is calling the shots, the price gap between them and cheaper major towns has started to grow again to 4p a litre. Although not as bad as last-year’s 5p or 6p excesses, the £2-a-tank difference for small cars and £2.80 for a Mondeo-sized vehicle will make more drivers again re-route their trips to take in the cheaper forecourts.

The AA adds that, arguably, a 2p-a-litre rise in the wholesale price of petrol since early March explains the price rise. However, with the NW European wholesale price of petrol back below $1000 a tonne after a month spell above and the pound worth nearly $1.7 last week, the pressure on retailers to put up prices should fall away.

If that happens but rural town prices fail to return to where they were earlier this year, resident drivers will know whether or not their local retailers have again set their sights on inflated margins for the summer.

‘Whereas supermarkets, faced recently with worse sales figures when fuel is factored in, have held their fire on pump price increases in cities and major towns, there are signs that some of them and other retailers are getting price-trigger happy again in rural towns,’ said Edmund King, the AA’s president.

‘A 2p increase in the wholesale price of petrol through March into April may justify that but, if pump prices stay higher while costs continue to fall back, rural town drivers will be tempted to look elsewhere for cheaper fuel – including nearly three million long-standing AA members now with free access to mobile fuel price tracking.’