Prices rise to a record high for the year – Budget increases and rising wholesale market costs are to blame.

Petrol prices are again topping £1 per litre for the first time in seven months. The average pump price across the country is 100.6p, according to fuel cost comparison site Diesel is 3.3p dearer.

World oil prices have climbed, but drivers have also suffered a 2p per litre increase announced in the Budget and imposed in April. A further 2p rise in fuel duty is planned for September. Meanwhile, oil prices hit a high for 2009 this week, reaching $69 a barrel. And, because it takes six weeks for changes in wholesale prices to affect whatever we pay, expect further price rises.

Back in February, the wholesale cost of a barrel was $38. And, at the start of the year, average unleaded prices dipped to 86p per litre, while diesel cost 98p per litre.

It pays to shop around, though: the dearest petrol in the UK is 110.9p per litre, while for diesel you can pay as much as 114.9p. But the cheapest unleaded is 95.9p, while it is still possible to find diesel for (just) under £1 per litre.