The price of petrol and diesel has edged back up over the last month, with diesel drivers getting a worse deal than petrol users, according to figures from the AA.

The average petrol price increased from 133.35p a litre in mid-May to 134.61p in mid-June, while diesel went up from 138.17p a litre to 139.16p. This comes after weeks of price drops (see the Cheap Petrol & Diesel guide).

Northern Ireland was found to have the most expensive petrol in the UK at an average of 135.8p a litre. London has the cheapest at 134.61p.

Similarly, Northern Ireland has the most expensive diesel at 139.8p a litre. London and south-west England have the the least expensive at 139.1p a litre.

The AA says the slight rise in average petrol prices represents "something of a lull" after the 8p-10p swings in prices over the last 12 months.

The motoring giant warns this year retailers have, on average, been "creaming up to £1 a tank extra off diesel car drivers and up to £1.40 a tank extra off diesel van owners".

AA president Edmund King says: "The clear message to diesel drivers is to take advantage of the greater range of prices locally. Some forecourts are more diesel-friendly than others."

To find the best prices in your area, use the website