In heated Commons exchanges over the 10 pits not covered by the moratorium announced on Monday, Mr Heseltine said: 'When a colliery is on the procedure and is going through the consultative process it is the responsibility of the coal board not to prejudice the outcome of that consultative procedure.
'And by that, as I understand it, it is their responsibility not to do anything that would preclude the continuation of that pit should the consultation produce evidence so to justify.'
Mr Heseltine went on to say that meant British Coal would have to exercise appropriate 'care and maintenance' to keep that option open.
But when asked by Dr Michael Clark, a rebel Tory and a member of the Commons Trade and Industry Select Committee, which is to carry out its own inquiry, why the 10 pits excluded from the Government's review were any different from the other 21, Mr Heseltine said the distinction was that the 10 were losing money.
While the exchanges served to sow confusion in the minds of some MPs, fuelled by use of words like 'procedure' and 'care and maintenance' the upshot remains that Mr Heseltine has failed to commit himself to the coal industry's colliery review procedure for any of the 31 pits on the original closure list.
The 10 pits British Coal still intends to close on economic grounds will now be the subject of 90 days' minimum notice under employment legislation, which is a significantly different and much more limited proposition.
It allows for unspecified 'consultation', but is not as exhaustive as the industry's own system, which even if unsuccessful, can delay closure for up to nine months.
Such a delay could mean the postponement of the Government's privatisation plans which are scheduled for the middle of next year.
Legal action by unions to force British Coal into the review procedure, which management has suspended, was adjourned until November at the High Court yesterday.
Mr Heseltine has yet to make a statement on whether the procedure will be used for the 21 collieries covered by the moratorium. He has not said what he means by a 'full and open review', but he is unlikely to invoke the industry's own mechanism without considerable pressure.
The coal board's procedure is often instituted where a warning has been issued by senior management about the future of a pit. Sometimes collieries will then introduce efficiency measures which ensure their continued existence.
However, none of the seven pits which have gone through the consultative machinery as far as an independent appeal panel have been reprieved.
Since 1985, when the present system was introduced, the panel has ruled in British Coal's favour in five out of seven cases. In another two it has accepted the validity of British Coal's financial calculations, but called for the mines to be kept open on social grounds. British Coal, which is duty bound to give 'full weight' to the panel's recommendations, closed the two collieries concerned.