The re-introduction of coal mining in Northumberland and Durham could ease Britain's energy crisis, unions claim.
Ellington was the last working colliery in the North East
The National Union of Mineworkers (NUM) says hundreds of millions of tonnes of coal could still be retrieved from coastal areas of the region.
The North East's last deep colliery at Ellington, near Ashington, closed earlier this year with 350 job losses.
A government review of Britain's energy policy is under way amid fears gas supplies may run short.
NUM chairman Ian Lavery said: "We can produce coal cheaply and burned with near zero emission levels, so why not begin production again?
"Basically, we have to understand that coal is a fuel of the future and not a fuel of the past.
"We have people all over the North East who would love to be working back down the pit."
Mr Lavery questioned the long-term cost effectiveness of nuclear and gas import options being considered by the government.
He added: "I would suggest that the reopening of the coalfields and associated clean coal technology in power stations will produce electricity far cheaper than anything else that is currently being considered."
Mr Lavery's comments come as the price of wholesale gas has almost doubled during the past week, prompting fears about winter supplies to industry in the UK.
Prime Minister Tony Blair has not ruled out an expansion of Britain's civil nuclear generating programme.
Thousands of gallons of water flooded into Ellington in January, prompting owners UK Coal to declare the mine economically unviable.