Labour's current lord chancellor, Charles Falconer, provided vital legal advice at the height of the miners' strike 20 years ago to enable the Thatcher government and the National Coal Board to assist the break-up of the National Union of Mineworkers.

Papers released to the Guardian show Lord Falconer was engaged in his then role as a barrister to advise Sir Ian MacGregor, brought in to run the coal board, on how to handle miners who defied their union leader, Arthur Scargill.