The STUC called on the Scottish government today for urgent action to save the mining industry from "imminent collapse."
About 450 jobs were left hanging in the balance after Scottish Resources Group, which owns Scottish Coal, announced plans to downsize to just two locations.
The company has blamed competition from overseas and the affect of cheap imports which have put global pricing trends at "record low levels."
But STUC economist Stephen Boyd said: "The Scottish government must now do what it can to support the company through this phase until the coal price recovers.
"We are increasingly concerned that, with coal prices low and falling, the coal production sector in Scotland is facing imminent collapse.
"As the Scottish government's recent Electricity Generation Statement recognises, Scotland will rely on coal fired power generation for the foreseeable future.
"It's simply unacceptable that this capacity will become reliant on coal imported from jurisdictions with low or no environmental and health and safety regulation.
"Coal and the bulk handling skills sustained by the coal production sector, are strategic assets which Scotland cannot currently afford to lose."
Mr Boyd said the job losses would be tragic for the workers, their families and fragile semi-rural economies which have never fully recovered from the loss of deep mining.
Scottish Resources Group mines at St Ninian's in Fife, Mainshill in South Lanarkshire and Binston Hill and Dalfond, both East Ayrshire, are said to be "working to a close" this year.
The two locations that will continue working as normal are at Broken Cross in south Lanarkshire, and Dunston Hill, east Ayrshire.
Scottish Coal currently employs 758 people.
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