Alan Clark, a maverick Conservative Party legislator who blew the whistle on British arms sales to Iraq, flaunted his philandering and flirted with Margaret Thatcher, has died. He was 71.

Mr. Clark, who was diagnosed with a brain tumor this year, died Sept. 5 at his home at Saltwood Castle, Kent, east of London, his family announced yesterday.

Labor Prime Minister Tony Blair paid tribute to Mr. Clark as "extraordinary, amusing, irreverent, but with real conviction and belief, and behind the headlines, kind and thoughtful."

A tall, gangling figure often accused of arrogance, Mr. Clark described as pointless and boring some of the posts he held as a minister from 1983 to 1992 in Prime Minister Thatcher's administrations.

He hung on to government jobs in employment, trade and defense, however, becoming a better-known national figure than many members of the Thatcher Cabinets--the inner circle to which she never admitted him.

He was a distinguished military historian. But it was his 1993 political diaries, published during a spell out of Parliament, that hit the bestseller list.

The diaries provided a gripping read, packed with unflattering descriptions of political colleagues, betrayals, incompetence and their author's serial extramarital affairs. "I deserve to be horsewhipped," he declared after a South African judge's wife accused him of seducing not only her but her two daughters. In his diaries, Mr. Clark referred to the trio as the "coven."

In the diaries, he wrote of addressing the House of Commons while "not entirely sober" and of brushes with the one woman to whom he appeared faithful--the prime minister.

He admired Thatcher's politics and her "pretty ankles." "I think she took it as her due that you should flirt with her," he once said.

"Politics is poorer and the world duller with his passing," Thatcher said.

In 1992, to the huge embarrassment of the Conservative government, Mr. Clark nonchalantly announced during the trial of three British executives charged with illegally exporting defense-related equipment to Iraq that he had encouraged the sales. Previous denials, he added, were a case of being "economical" with the truth.

The executives were acquitted and the government sharply criticized in a judicial inquiry.

Alan Kenneth McKenzie Clark was born April 13, 1928, the elder son of Lord Kenneth Clark, the eminent art historian who made the internationally acclaimed TV series "Civilisation."

Like many English boys of his background, Mr. Clark grew up seeing little of his parents. He was sent to boarding school at the age of 8, and then Eton and Oxford, where he studied law.

He was elected to Parliament in 1974 to represent Plymouth, a southwest England constituency.

Early on, he acquired a reputation for what admirers saw as a refreshing lack of political correctness and what critics regarded as offensive views. He opposed closer integration with the rest of the European Union and was a passionate campaigner for animal rights. He was a vegetarian and an opponent of fox hunting, and he once owned a dog named Eva Braun, after Hitler's mistress.

Mr. Clark inherited a fortune, including the 12th-century Saltwood Castle.

But nothing apparently was as good as the House of Commons.

Retiring once from politics in 1992, he made a successful comeback five years later. Nearly 70, Mr. Clark secured the nomination for London's Chelsea and Kensington district, haunt of the mega-wealthy and the most secure Tory constituency in Britain. He returned to the Commons in May 1997 elections in which the Conservatives lost power to the Labor Party.

His wife, the former Jane Beuttler, whom he married when she was 16 and he was 30, always stood by him with a brittle smile.

"He's absolutely dreadful. . . . But I still love him," she said of the troubles with other women, dating from when one of his former girlfriends showed up on their honeymoon.

Survivors include his wife and two sons.