It was the second blockade of Shell's Stanlow refinery in Cheshire in the last five weeks.

About 500 people gathered outside the refinery during Friday, with numbers dwindling to about 100 late in the evening, according to one demonstrator, who declined to give his surname.

Geoff, 46, a haulage contractor, said the protesters had prevented about 90 tankers from leaving the oil refinery by standing in the road.

He said the tankers had parked up and their drivers were supportive of the demonstration.

Geoff, a father-of-four from Cheshire, said: "We're trying to put pressure on the Government and the oil companies to bring the prices down because basically they're ripping us off. If they don't drop the prices they're going to start putting us out of business."

He said police were at the scene, adding that protesters were intending to continue the blockade for "as long as it takes to get the message across".

Cheshire Police declined to comment on the protest. A telephone operator said: "The duty inspector is not taking any calls on this."

The protest came as the price of oil reached a new high, shooting up more than 10 US dollars to a new record above 138 dollars a barrel. Analysts predict prices could hit 150 dollars within a month.

A spokesman for Shell said he believed there were about 60 protesters and they had delayed about 20 tankers.