A mammoth legal battle was looming last night over compensation for thousands of ex-miners who suffered knee injuries.

At a court hearing yesterday, it was agreed that a register of potential claimants could be opened, allowing men and their families to state a formal interest in pursuing damages for diseases such as osteoarthritis - suffered in knee joints as a result of prolonged kneeling and crouching in coal tunnels.

But the Department of Trade and Industry (DTI), which says no evidence has yet been produced to show it should accept liability for the injuries, indicated it was willing to fight the claim all the way to the High Court.

Bleddyn Hancock, general secretary of mining union Nacods South Wales, which is leading the claim, said the Government had gone back on a pledge to allow mediation between the two sides.

He said: "All this would be unnecessary if the Government would sit down with us and agree a scheme. Instead, crippled miners will now be made to fight to what will be the bitter end."

Robert Jay, representing the DTI, said the claim would end up in the High Court, given the cost should mining unions win their fight.

Mr Jay said the case had already taken a large amount of time already taken with the case, but the two sides were "not even in the starting blocks yet".

He said the claimants did not yet know whether they have a good enough case to take to the High Court and would not begin to know until they had seen former British Coal documents.

The claim, begun by Nacods South Wales, is also being funded by the Scottish, Durham and Derbyshire branches of the National Union of Mineworkers, along with the Durham Mechanics Association.

Once a register is opened, possibly as soon as today, men who meet medical criteria will be able to claim, along with relatives of miners who have passed away.

However, claimants not represented by the five unions will have to meet their own costs should they wish to join. Unlike the previous two compensation schemes set up for former miners - for lung problems and Vibration White Finger - no legal aid is available.

Judge Simon Grenfell, sitting at Leeds Crown Court, said he hoped that both parties would be in a clear position to set out the central issues to both their cases by November.

Jim Perry, of the Durham Mechanics Association, which has about 3,000 members, said it already had the names of a number of men who could help make up the lead cases in the claim.

He said: "We are giving this claim our best shot. However, it will be the same as with Vibration White Finger and chest diseases, it will take an awful long time to proceed."