Fuel duty campaigners are demonstrating outside a Cheshire oil refinery in protest at high fuel costs.
The protest began at 0500 BST, police said
They are the same protesters who organised nationwide action at fuel depots in 2000.
By setting up outside Stanlow oil refinery near Ellesmere Port, they want to make fuel prices an issue in the election, said organiser David Handley.
A spokeswoman for Shell said that Monday's protest had not caused any disruption to the fuel supply.
The protest was made up of 14 tractors and about 20 people on foot and began at about 0500 BST.
Mr Handley, one of the founders of the Farmers for Action group, said he wanted politicians to address the issue of fuel prices.
"In 2000 they [the government] promised they would look at the situation in relation to fuel and fuel tax.
"Here we are in 2005 and the government of the day don't even seem to be having it on the agenda," Mr Handley said.
He added that he had had a "good meeting" with Shell representatives.
"They started off by telling us they had no influence at all over government but, by the end, they were telling us how often they met with governments to talk about the rising price of fuel."
The protest failed to get the support of the tanker drivers' union, the TGWU, but Forum of Private Business says it has "great sympathy" with demonstrators.
It says it is concerned that the new government will increase duty later this year.
At lunchtime, the protesters decided to continue with their demonstration.
Tom Houghton, a Farmers For Action organiser, said: "It was a unanimous decision to stay.
"We are determined to get the issue of fuel on to the politicians' agenda for this General Election and we will do what it takes.
"We have been told there are farmers and hauliers planning on coming out to support us."
Cheshire Constabulary said the protesters' vehicles had circled a nearby roundabout for three hours before the drivers agreed to park them on the central reservation of the roundabout.
The police spokeswoman said the protest was not the same as that in 2000, which saw fuel supplies around the country run dry.
A spokeswoman for Shell said that tanker movements had not been disrupted and there has been no impact on supply.
"We are monitoring the situation closely and have contingency plans to deal with a range of scenarios that may affect our operations.
"We would like to reassure our customers that we will do our very best to ensure there is no interruption to supply."