The company had first proposed mothballing idea in November 2012 for a mine which is one of the UK’s last working deep mines, on health & safety, geological and financial grounds.

Following discussions with employees and trades union representatives and due consideration to alternative proposals, the company concluded that no viable alternative solution existed.

The mothballing process will begin with immediate effect is scheduled to complete in March 2013.

The company is projected to witness an operating loss of £10.4m from the colliery’s closure for the current financial year and a full year loss of £8.2m.

Mothballing process includes the completion of the last strips of coaling on the T15 panel and equipment recovery at an estimated cost of around £12.3m, comprising £10.4m in cash costs.

The colliery, meanwhile, will continue to harvest and process the remaining one million tons of surface coal fines.