UK Coal 'may close Daw Mill colliery'. Daw Mill colliery The mill could be closed by early 2014 when current coal panels will have been exhausted Related Stories. The owners of the UK's biggest deep coal mine are considering closing the colliery in North Warwickshire, jeopardising 800 jobs. UK Coal is consulting on closing Daw Mill in Arley under plans to restructure the business. The mill could be closed by early 2014 when current coal panels will have been exhausted. UK Coal said the mill has "considerable long-term resources" but production is 175,000 tonnes behind budget. Work to extend production beyond 2014 has stopped. The company said an increase in production and a fall in operating costs in coming months could secure its future, but it said the mine would only be sustainable under a "lower risk operating model". Andrew Mackintosh from UK Coal said: "Daw Mill may well close...we don't know if that's going to be a permanent closure or a different type of closure, a mothballing effectively, but that is the possibility at the moment." Dave Meuse, Union of Democratic Mineworkers (UDM) branch secretary at Daw Mill, said: "The unions at Daw Mill are fully committed to assist UK Coal in providing a long term future for Daw Mill." He said the UDM had about 430 members at the mine. UK Coal returned to profit earlier this year for the first time in four years, but chairman Jonson Cox recently said Daw Mill was the greatest risk to output this year due to a change in the coal face.