Trade unions have criticised the government for ruling out using state aid to save the Coryton oil refinery in Essex, as time runs out to save 850 jobs at Britain's largest independent site.
Ministers said overcapacity in the industry meant that pumping money into Coryton while administrators search for a buyer would be unsustainable.
The Department for Energy and Climate Change said: "This would not be a long-term solution either for the taxpayer or for the industry, which will thrive best with open and fair competition."
Coryton's administrators are winding down the site, after halting refining work last week, and hope to sell it as a storage facility.