LAST-MINUTE talks to avert a fuel strike began today as 500 petrol tanker drivers prepared for a four-day walkout.

Motorists were urged not to panic buy as the drivers got ready to launch their strike from Friday - as unleaded petrol was predicted to soar to 230p a litre.

Gordon Brown's spokesman said emergency plans were in place to minimise disruption during a strike and stressed: "We want the public to buy as normal, to avoid creating problems."

The Downing Street plea comes with diesel prices poised to soar past £6 a gallon.

Warnings that a litre of unleaded could hit 230p followed Russian energy giant Gazprom's prediction that crude oil was set to skyrocket to $250 a barrel `in the forseeable future'. It peaked last week at a fraction under $140.

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 Britain.

In a last-ditch attempt to avert strike action, talks led by conciliation service ACAS were being held today.

Contingency plans for a strike include allowing suppliers to share information about stocks without falling foul of competition laws. Fuel supplies to the emergency services would also be maintained in the event of shortages.

The pay row has erupted because members of Unite claim they are paid the same now as they were in 1992, just under £32,000 a year, despite their working week being 11 hours longer.

Bernie Holloway, spokesman for Hoyer, the biggest of the two transport companies involved in the dispute, said it was `disappointing' that Unite had rejected an 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 repeated its call for Shell to get involved in the dispute and stop `sitting on its hands'.

Unite's Len McCluskey said: "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."

However, the petrol giant is refusing to get involved and reiterated calls for the two sides to resolve the dispute.

A spokesman for the Department for Business 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.