Mr Heseltine gave a commitment that Britain would not breach its international obligations on the environment when he faced questions from the cross-party Commons Select Committee on Environment.
Andrew Warren, an adviser to the committee and director of the association for the conservation of energy, said that to meet that commitment, there would have to be a 'big drive' for fuel efficiency in the White Paper to be published by Mr Heseltine later this month.
The Government is committed to cutting CO2 emissions to 1990 levels by 2000. That would require a cut of about 10 to 19 million tonnes of carbon. But the rescue of half of the 31 pits, recommended by the Commons Select Committee on Trade and Industry, would add an estimated 3 to 5 million tonnes of carbon to the atmosphere. 'If coal becomes sacrosanct, you can only do it by looking at fuel efficiency measures. What has to be in the White Paper are big plans, mostly on building,' Mr Warren said.
Mr Heseltine was sharply criticised for refusing to give any details about the White Paper. He was accused of acting 'cynically' and 'passing the buck' by Robert Jones, the committee's Tory chairman after Nick Raynsford, a Labour member of the committee, questioned Mr Heseltine about his views before Lady Thatcher's downfall.
Mr Raynsford quoted a Tory Reform Group document in 1990, when Mr Heseltine said the Government's international commitments on carbon should be 'the floor, not the ceiling'.
Mr Heseltine replied: 'Ah, yes, I was a backbencher then . . .' He added: 'Until we have the White Paper, the facts and the figures must be something I cannot be drawn on.' Mr Jones expressed concern at the failure to produce answers on the environmental impact of the pits rescue and told Mr Heseltine he could expect to be called back to be cross-examined after the White Paper was published.