Average UK petrol prices have fallen by 2ppl in the past month but towns with the “wrong” mix of supermarkets are paying 3ppl more than their neighbours with competitive superstores, according to the latest AA Fuel Price Report.

Mid-August petrol pump prices average 110.22ppl compared with 112.19p a month ago, while the diesel average has dropped from 112.69p to 111.18p a litre in the past month. The petrol average had fallen to a low of 109.70p, but increasing oil prices, once again closing in on $50 a barrel, reversed the decline.

Further weakness in the pound, worth less than $1.30 dollars last week compared to $1.32 a month ago, has also made oil, which is priced in dollars, more expensive. This time last year the pound was worth $1.56, which would have reduced this month’s average petrol price to around 105ppl (a summer price last seen in September 2009). With Asda regularly trading at 3p below the UK average and 4.5p below in December, the clamour would have been for a return to the £1 a litre.

Petrol demand in July slumped to 1.42 billion litres, after topping 1.5 billion litres the previous month, for the first time since August 2014. Diesel consumption remained steady at 2.53 billion litres compared to 2.59 billion litres in June.