London — The resignation of Margaret Thatcher's most loyal lieutenant - a man who has done more to smooth the way for her social revolution than any other Cabinet member - is a heavy political blow. An unlikely ally whom Mrs. Thatcher defeated 13 years ago for the leadership of the Conservative Party, William Whitelaw has resigned his posts as deputy prime minister and leader of the House of Lords on the advice of doctors and his family. In a letter of resignation delivered Sunday, he praised Thatcher's leadership and promised his continuing support in the House of Lords where he remains a member.
The prime minister accepted his resignation ``with a great sense of loss,'' according to the Times (of London). Lord Whitelaw is widely regarded as an irreplaceable asset for the prime minister at a time when Thatcher is pushing through Parliament radical legislation in education and tax reform. She is also trying to prevent divisions within her own party.
Whitelaw has been valuable as a reconciler of differences, notably within the Conservative Party itself. This was especially true soon after the Thatcher government came to power in 1979 when disputes within the Cabinet about her program threatened to divide the Conservatives.
His leadership style differs from that of the prime minister. A gregarious man who can speak in honeyed words, he can offer the extravagant courtesy of the landed aristocrat, endless patience, and according to one of his critics, ``ruthlessness disguised as common sense.'' During a 33-year career in politics, ``Willie'' Whitelaw seemed addicted to power, though he stopped short of the highest office. He faithfully served in the governments of four prime ministers in a series of high posts unrivaled by any of his active contemporaries today. He was unswervingly loyal to the Conservative Party, regardless of its leadership.
A liberal on social issues and an agnostic on matters of economic ideology, he combined integrity, balance, and a willingness to compromise. He also has a sense of humor. He told a BBC interviewer last year that one secret of his success was a readiness to apologize for almost anything at any time.
Whitelaw never minced words. In a meeting with American journalists last year, he acknowledged that the government faced very difficult challenges in 1988, especially the controversy over Britain's National Health Service, the last major area of British life untouched by the Thatcher revolution.
``We are in trouble over this - political trouble,'' he said about the funding crisis in the health service. ``Those who think we can buy our way of it are living in a fool's paradise.''
Thatcher has appointed Whitelaw's deputy, John Belstead, his successor as leader of the House of Lords. The prime minister may leave the post of deputy prime minister unfilled, however.