Overview:In her second term in office after victory in 1983, Mrs Thatcher's position seemed impregnable. Her conduct of the Falkland's war was popular, she had trounced Arthur Scargill and the striking miners, and had survived the bombing by the IRA of the Grand Hotel in Brighton. But all was not well: Cabinet Secretary Robert Armstrong and ex Chancellor Nigel Lawson are amongst those who recall the emnity between the Prime Minister and her Defence Secretary Michael Heseltine. Thatcher thought of him as 'over-poweringly ambitious and self-centred', and his handling of the Westland affair in 1986 only served to increase ill-feeling between the two, which reached its height with his challenge to her leadership in 1990.