Unions at troubled Kellingley Colliery have written to government ministers urging them to secure a long-term future for the pit.
UK Coal - backed by £20m of investment from the government and private sector - plan to close Kellingley, with the loss of 700 jobs, by December 2015.
But, a report published on behalf of the Trades Union Congress (TUC) and the National Union of Mineworkers (NUM) claims the deal would cost the government a total of £75 through loss of income tax and costs in unemployment benefits.
Instead, the unions urged the government to apply for European Union state aid, which they claim would keep the pits open until at least 2018.
Chris Kitchen, National Union of Mineworkers (NUM) general secretary, said: “This report shows that it’s actually in the public interest to keep the pits open rather than putting money in to put the men out of work.
“I’m hoping the government will listen to us that’s why we’ve spent so much money on the report.
“It’s a conservative led coalition, with a Conservative energy minister, and there’s obviously a lot of history between miners and the Conservatives.
“But this report has been done by an independent consultant and it proves it would be more beneficial to fund a longer-term future than fund a closure of the pits.”
Andrew Mackintosh, UK Coal’s director of communications, said the firm was still working on a deal to prevent an immediate closure of Kellingley.
He said: “UK Coal has always been open to try and find someone with enough money to keep the business sustained.
“We appreciate the TUC and NUM’s views but our main concern is to agree the 18-month deal and that has to be done very soon.”