Last-ditch talks aimed at averting a strike by hundreds of fuel tanker drivers who deliver fuel for Shell have broken down, the Unite union has said.
The strike over pay will start at 0600 BST on Friday and continue until 0600 the following Tuesday.
Unite warned that the industrial action would affect supplies at all of Shell's 1,000 UK forecourts within 24 hours.
The government urged both sides to resume talks and asked motorists to buy only the fuel they need.
"Our primary concern is for motorists who may suffer inconvenience as a result of Unite's imminent industrial action," said Shell in a statement.
"Regrettably, it is inevitable that it will have a significant impact on our petrol stations," the firm said.
'Costly strike'
The drivers work for two companies, Hoyer UK and Suckling Transport, which deliver fuel for Shell.
This dispute could have been resolved if Shell had advanced a fraction of the billions of pounds in profit it makes every month
Len McCluskey, Unite union assistant general secretary
During the talks, the firms increased their pay offer, which they union said was "not sufficient".
"We extended our offer to the very limits that our business could sustain," said Bernie Holloway from Hoyer UK.
"We are disappointed that our improved offers have been rejected. Unfortunately, it looks likely now that there will be a damaging and costly strike," he said.
The Unite union criticised Shell's refusal to get involved in the pay negotiations.
Len McCluskey from Unite on why talks broke down
"This dispute could have been resolved if Shell had advanced a fraction of the billions of pounds in profit it makes every month," said Unite's assistant general secretary Len McCluskey.
"One of the world's richest companies is prepared to play Pontius Pilate and see the British public inconvenienced rather than settle this dispute for a sum smaller than the chairman's pay increase last year," he said.
We have been working closely with industry to put in place detailed contingency plans
John Hutton, Business secretary
Hoyer UK and Suckling Transport had offered a pay rise of 6.8%. At the start of talks on Thursday they put two new offers to the Unite union.
They offered an increase of 7.3% backdated to 1 January 2008, which the companies said would take drivers' average earnings to over £39,000.
The firms then offered a further 6% increase from 1 January 2009, which would take earnings to about £41,500.
'Emergency response'
The government said it would try to minimise the impact of the industrial action on motorists.
"We have been working closely with industry to put in place detailed contingency plans to reduce as far as possible the disruption for the driving public," said business secretary John Hutton MP.
The government has allowed fuel companies to share information in order to get supplies of petrol and diesel to where they are needed during the strike, while remaining within the scope of competition law.
It also has the option of using a number of "emergency response tools" in the event of any fuel shortages. These include:
Limiting the amount of fuel that retail customers are allowed to buy at any one time
Prioritising the supply of fuel to ensure adequate supplies to the emergency services and other key services such as utility companies
Encouraging motorists to use less fuel
This week Shell set up a dedicated team to work on ways to minimise any disruption in the event of industrial action by maximising stocks of fuel at its petrol stations and prioritising deliveries.
Bookmark with:
What are these?