Shell last night started cutting the price of unleaded fuel at its motorway service and trunk road petrol stations from 83.9p to 79.9p per litre.

Shell said the cut reflected the lower price of crude oil, which has been falling since November as supplies from the Middle East have picked up.

Super unleaded will be reduced from 89.9p to 86.9p, lead replacement petrol will be cut from 89.9p to 85.9p and diesel from 86.9p to 84.9p.

Shell said it was restricting its cuts to 250 of its 1,100 service stations because at other sites local competition meant unleaded petrol was already around the 79.9p mark.

BP Amoco indicated it could follow Shell's lead, although it had no plans yet to cut its prices. A spokesman said the group intended to remain competitive. "If the market is moving downwards, then no doubt we will too," he said.

This month, Shell became the first big oil company to join the leading supermarkets in a price-slashing exercise as falls in the price of crude oil began to filter through to the pumps.

In September lorry drivers held a nationwide protest at high diesel prices. A second protest in November, however, failed to capture the public imagination.

Press Association