Petrol and diesel prices have risen for eight out of the past 12 months, bringing both to 13p per litre (ppl) higher than during this time last year, according to new data from RAC Fuel Watch.

In August, petrol increased by 1.65p to 130.59ppl, while diesel increased by 1.32p to 132.19ppl. In 2017, these values were at 117.51ppl and 118.37ppl respectively.

These increases are largely attributed to the weak pound, combined with the price of oil per barrel reaching over $70.

The average petrol price in the UK is consequently at its highest level since July 2014, with diesel reaching its most expensive since October 2014.

For comparison, per barrel oil prices were at $106 while the pound was worth $1.70 during 2014. During August 2018, oil per barrel reached $77.54 and sterling was worth $1.29. Despite the lower oil price, the significantly weakened pound has ensured that both petrol and diesel are far costlier for retailers to purchase on the wholesale market.

Filling a 55-litre family car with unleaded petrol is 91p more expensive than in July, and £7.32 more than during 2017. The equivalent cost for diesel has risen to 73p more than July, and £8.19 more expensive than last year.

Motorists in the North East and Scotland witnessed the most significant rise in the price of unleaded in August, increasing by 1.81p a litre. However, the South East topped the list for most expensive place to buy unleaded, reaching 131.46ppl.

Diesel increased the most in the North West and South East regions, rising by approximately 1.48p per litre. The South East was also the costliest place to buy diesel in the UK, reaching 134.03ppl.

Simon Williams, RAC fuel spokesperson, said: “With many factors at play on the global oil market the price of a barrel could easily break through the $80 mark and stay there.

“If this were to happen it would be dire news for drivers and we could even see pump prices heading towards the record highs of April 2012 when petrol hit an average of 142p a litre and diesel 148p.”