Kellingley is due to take some miners from the Selby pits

About 350 workers at the Kellingley pit are staging a 24-hour stoppage against plans to change their conditions.

Owner UK Coal wants to increase the site's operating hours to accommodate 240 miners from the Selby complex.

But members of the National Union of Mineworkers (NUM) say they will seek a High Court injunction unless the company abandons the plans by Thursday.

Spokesman Chris Kitchen said the NUM believed employment contracts would be broken if the new arrangements were imposed.

He told BBC News Online: "We've tried everything else and when we got the ballot result it was clear the feeling of the men was very strong.

"If it didn't work [the strike] - the only other option open to us was a legal challenge.

"We have learnt the hard way that striking doesn't always solve the dispute."

Progress 'difficult'

UK Coal wants to increase Kellingley's operating hours from 95 to 145 a week to bring it in line with the working arrangements currently used by miners at Selby.

Spokesman Stuart Oliver confirmed the company intended to contest the injunction.

He said the dispute reached a stalemate after the NUM refused to discuss the issue of flexible working at its last meeting with UK Coal.

"At that meeting they refused to talk about flexible working - which is the core of the dispute.

"It makes it very difficult to make progress when the other party involved will not talk about the needs of the business."

The NUM has described the proposals as "anti-social" and argues they would result in men working 12 hour shifts in "hostile conditions" underground.

Another 24-hour stoppage is planned for Thursday.