Ministers were tonight urged to meet workers at an oil refinery set to be made redundant and explain why they are not using state aid to help save jobs.
Unite accused the Government of "betraying" workers at the Coryton oil refinery in Essex after a decision not to apply to the European Commission for permission to use state funds to keep it open while efforts continued to find a buyer.
Unions, politicians and other campaigners have been pressing ministers to consider putting up cash to keep the refinery going until administrators can find a buyer as its closure would drain £100 million from the economy.
But ministers said overcapacity in the refining industry meant it would not be sustainable to provide government help.
Unite said Energy Secretary Ed Davey should meet the 850 workers, accusing the coalition of "double standards" after £100 billion was offered to banks for lending purposes.
General secretary Len McLuskey said: "Last night, the Chancellor pledged to pump in at least £100bn into the banking system to boost lending - which bankers should be doing anyway as that's their job - in an attempt to build a financial firewall against the situation in Greece.
"Yet, a similar request from Unite for state aid in the short-term to tide over Coryton until a viable buyer is found to take over the oil refinery is dismissed by ministers out-of-hand.
"This is simply not good enough. Ed Davey and his ministerial team should have the courage to get in their limos and drive to Coryton to tell the workers why they have to lose their jobs, while bankers in the City scoop up outrageous and undeserved bonuses."
GMB union official Phil Whitehurst said: "How can the Government just sit back and let 850 refinery workers lose their jobs?
"Most will not be able to get work in the immediate area in their specialised professions.
"The closure will also have a devastating effect on local businesses and the supply chain to the refinery."
Thurrock Council commissioned an economic impact assessment of the closure or change of use of the site, which found it would cost £30 million in wages, £26 million in contractor costs, £6 million in locally sourced materials, £40 million spent on chemicals and utilities, and £5 million in business rates.
A Government spokesman said: "It is extremely disappointing that the administrators haven't been able to find a buyer who could provide investment required to keep Coryton operating as a refinery.
"Departments across Government have looked very carefully at whether or not state aid should be provided for Coryton.
"But we have come to the conclusion that the existing overcapacity in the refining industry and declining demand for petrol mean that it would not be sustainable.
"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.
"If Government did step in to help Coryton, this would be a short-term fix, and it could potentially lead to job losses at other refineries who would be at an unfair disadvantage to Coryton.
"This was a very difficult decision and it is particularly regrettable that people may lose their jobs.
"We are working with local agencies and Jobcentre Plus to ensure the right support is in place if it's required to help these skilled workers find new positions.
"The closure of Coryton as a refinery should not have any impact on supply of fuel to London and the South East. There are many other supply points and operational refineries which can be used."