Last Bid To Avert Tanker Strikes
Unions representing 500 oil tanker drivers planning a four-day strike are to take part in last-minute talks in a bid to avert it.
Members of Unite working for two firms on contracts with Shell are locked in a pay dispute.
If their walkout goes ahead on Friday it will affect one in 10 filling stations across the UK.
The government has already urged motorists not to panic buy fuel because of fears of petrol shortages.
A spokesperson for Prime Minister Gordon Brown said contingency plans were in place to minimise disruption.
He said: "We want the public to continue to buy as normal so as to avoid creating problems that might otherwise not exist."
'Fairer wage'
Even so, the government said some petrol stations could run out of fuel.
Hundreds of members of Unite are due to walk out from 0600 BST on Friday until 0600 the following Tuesday in a dispute over pay.
The drivers work for Hoyer UK and Suckling Transport, haulage firms employed by Shell to deliver fuel to its forecourts across the UK.
The union claims drivers' average pay before overtime of £32,000 has not increased since 1992. It suggests a wage of £36,000 a year would be fairer.
Drivers have rejected an improved offer of a 6.8% pay rise, which the companies claim would have increased drivers' average salaries, including overtime, from £36,500 to around £39,000 a year.
Hoyer UK estimates that that if drivers had accepted that latest offer, their average pay would have increased by a third over the past five years.
In an attempt to resolve the dispute, union representatives are due to meet the two transport firms for talks led by conciliation service ACAS later.
Bernie Holloway, spokesman for Hoyer, said it was "disappointing" that Unite had rejected the improved pay offer.
"We believe this was a very good offer that would take the average drivers' pay up to around £39,000," he said.
Unite renewed its insistence that Shell should intervene to resolve the dispute.
Avoid disruption
General secretary Len McCluskey said: "It is no use Shell bosses, who have themselves enjoyed 15%-plus pay increases in the last year, sitting on their hands.
"They have 72 hours to start focusing on avoiding the disruption this will cause to the general public, who are already mindful of the staggering profits Shell rakes in."
In a statement, Shell said it "urged both parties to find a way through their differences".
The Department for Business, Enterprise and Regulatory Reform (BERR) estimated that Shell accounted for about one in 10 filling stations in the UK and that it was "inevitable" some of them would run out of fuel.
Shell is understood to have a dedicated team working to minimise any disruption by maximising stocks of fuel and prioritising deliveries.