Members of the UDM at pits operated by RJB Mining are in dispute with management over pay.

The UDM said its members at the country's biggest coal producer, had voted by 56.1% in favour of industrial action.

Over 2,000 workers have been balloted over a pay deal which the union complains will lead to below-inflation increases for the next five years.

The UDM was formed during the bitter strike of the mid-1980s by workers opposed to the walkout by the National Union of Mineworkers.

It has never even balloted on strike action before this vote.

The NUM, led by Arthur Scargill, is due to ballot its members at RJB next week.

Anger

UDM president Neil Greatrex was "delighted" with the outcome of the ballot.

"There is a lot of anger and dissatisfaction among our members, considering what they have achieved for the company.

"People have been saying that enough is enough. We will now discuss the ballot result before deciding our next move."

The union will have to give seven days' notice before a strike is held.

Crucial time

A spokesman for RJB said: "Less than a third of the 2,500 industrial employees in the Midlands coalfield have voted for industrial action.

"It is evidence that the majority want to continue working. We would urge all UDM members to report for work as normal to avoid breaching their conditions of employment."

RJB says new incentive and bonus payments mean that pay rises will keep pace with inflation.

The company is currently negotiating with National Power over additional sales needed to secure output from pits in Yorkshire.