A planned strike by oil tanker drivers was attacked by Downing Street today as motorists were urged not to start panic buying.
Hundreds of members of the Unite union employed by two firms working on Shell contracts are due to walk out from 6am on Friday until 6am the following Tuesday in a pay dispute which could hit one in 10 filling stations across the UK.
Prime Minister Gordon Brown's spokesman said contingency plans were in hand to minimise disruption - using new measures put in place last week to deal with such situations.
He told reporters: "We believe that this strike is unnecessary and we would want to ensure that nothing was done that inconvenienced the public.
"But the most responsible thing the public can do is to continue to buy as normal."
Talks aimed at averting the strike will be held at a secret location tomorrow.
Bernie Holloway, from Hoyer, the biggest of the two transport companies involved in the dispute, said it was "disappointing" that Unite had rejected an improved pay offer last week.
"We believe this was a very good offer that would take the average drivers' pay up to around £39,000."
Mr Holloway added that he hoped that tomorrow's talks, at the conciliation service Acas, would break the deadlocked row.
The union said its improved offer, made during a meeting last Thursday, was worth 6.8 per cent.
Meanwhile, Unite repeated its call for Shell to get involved in the dispute.
A spokesman for the Department for Business, Enterprise and Regulatory Reform said it was "inevitable" that some petrol stations would run out of fuel if the industrial action went ahead.
"If the strike were to affect other retailers it would have a more significant impact," he added.
Downing Street said contingency measures included allowing suppliers to share information about stocks without falling foul of competition laws.
"The Government is working with the wider fuel industry on what could be done to reduce any disruption to the public and business," the PM's spokesman said.
"There are established procedures in place and these were recently used to good effect in Scotland during the Grangemouth dispute.
"There is an established memorandum of understanding with the fuel industry which has been in force since last Friday. This allows the industry to work more closely with the Department for Business while remaining within the scope of competition law."
He said it was disappointing that talks had failed to produce an agreement but welcomed the involvement of Acas.
"We encourage both sides to get back to the table to reach a resolution to avoid any disruption to people's lives and livelihoods.
"We do not believe that any strike action is justified because that would disproportionately impact on the lives and livelihoods of millions of people in the country not involved in this dispute.
Asked if he feared panic-buying, he said: "We want the public to continue to buy as normal so as to avoid creating problems that might otherwise not exist."
Unite assistant general secretary Len McCluskey said: "Only Shell sets the terms of this contract and only it can solve this dispute. This is one of the most profitable companies on earth and it now needs to provide the financial flexibility to avert this dispute.
"It is no use Shell bosses, who have themselves enjoyed 15 per cent-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.
"Shell tanker drivers are earning exactly the same today as they were 15 years ago while working for a company that makes £1.3 billion every month, profits our members' hard work helps deliver.
"So Unite is saying to Shell bosses, stop hiding behind your sub-contractor and help us sort out a solution.
"This dispute could be settled for less than £1 million, an amount that would not put even the slightest dent in Shell profits."
Unite said Shell tanker drivers earn a basic wage of just under £32,000 a year for a 48-hour working week, a similar amount to what they were paid in 1992.
Shell's board members typically received a 16 per cent increase in their pay packets last year, the union claimed.
The strike is due to start from the first shift on Friday until the end of shift on Monday, hitting 14 terminals across the UK.
Shadow business secretary Alan Duncan said: "At a time when oil prices are already high from global pressures, the last thing that British consumers need is more logistical disruption.
"John Hutton has so far taken the right course of action, although it is typical that we have so many labour disputes under a Labour Government.
"The unions are being utterly irresponsible - their action will have a massive impact on the very people they claim to represent."