Workers have been in dispute with pit owner UK Coal over the introduction of new working conditions at Maltby Colliery near Rotherham, South Yorkshire.

The company has warned it will be forced to close the site with the loss of 500 jobs unless workers sign up to the new agreement.

Nacods, the union representing the miners, said 92% of members voted in favour of the new deal on Friday.

UK Coal says the site, which reported losses of �83m in 2002, cannot continue to operate without the changes.

Speaking in April, company spokesman Stuart Oliver said: "Without flexible working Maltby Colliery will not be viable. We can't continue to operate non-viable pits."

The UK's biggest coal producer operates 12 pits and employs about 7,000 people.