More than 850 jobs could be lost after the administrators at an oil refinery failed to find a buyer or the cash needed to keep it going.
The Coryton plant in Essex, which is the biggest provider of petrol and diesel in the south east of England, was plunged into administration by its Swiss owner Petroplus in February.
The plant supplies 20% of fuel in London and the South East.
Administrators PwC said the site would be wound down over the next three months after the challenge of raising the £625m needed to fund the refinery proved too much.
There are likely to be a "substantial" number of redundancies among the 500 workforce, PwC said, while around 350 contractors will learn their fate in the next few days.
A spokesperson for the department of energy and climate change said: "It is disappointing that PWC has been unable to find a buyer for Coryton. This is particularly bad news for the workers at Coryton.
"The Job Centre Plus Rapid Response Service is available to support individual employees to re-enter the job market. Coryton’s workforce is highly skilled and well-positioned to take advantage of new opportunities.
"We want to reassure people that there will not be any impact on fuel supply from this development. Continuing jetty operations at Coryton means that there should be no loss of supply through the terminal to London and the South East.
"Closure of the refinery reflects overcapacity in the European refining sector and there have been a number of refineries have closed across Europe in recent years.
"We will continue to keep in close contact with the administrators PWC who are looking at further options for the future of the facility”.