Motorists are facing fuel shortages with some garages running out of petrol as they struggle with the after-effects of the Buncefield oil depot blasts.
The Buncefield depot fire caused extensive damage
Both the Hertfordshire depot blast and a seasonal peak in petrol sales have led to supplies being disrupted.
Some garages in the south-east have completely run out with others running short, fuel retailers have confirmed.
They have urged against panic buying and say they will be able to restock in the next couple of days.
A series of explosions destroyed the depot - the fifth largest in the UK.
Damage to the distribution terminal, owned by Texaco and Total, has hit the supplies of a number of petrol retailers with fuel being brought in from elsewhere and lorries forced to travel greater distances.
The situation has been made worse by high demand in the run-up to Christmas.
"There are some shortages at stations in south-east England and into the Midlands," a Shell spokesman said.
"It is connected to Buncefield.
"We are working hard to get fuel to those stations which have run out."
A Total spokesman said: "Some of our service stations are experiencing short-term supply issues as we re-order our distribution following Buncefield, but we are working hard to resolve the situation and our normal service levels should return."
But the Federation of Petroleum Suppliers warned that further shortages were likely.
"Buncefield was a very, very major supply source of fuel for the whole of south-east England," spokesman Rod Prowse said.
"When you have to fall back on alternatives, they are never quite as good.
"I'm sure in the months ahead there will be recurring problems."
The UK Petroleum Industry Association, however, said the shortages were "just localised effects" rather than a widespread long-term problem.
The Buncefield blast is still having an impact on restaurant chain McDonald's, after it closed one of its supply centres based close to the depot in Hemel Hempstead.
Notices in London restaurants are warning customers that some items are unavailable because of problems with supplies.