They must have made an odd couple, even for a furtive romance. Young Winston Churchill, grandson of the wartime prime minister, clean-cut, confirmed family man and, not so long ago, the rapidly rising "golden boy" of British public life. And Soraya Khashoggi, self-created exotic jet-setter and ex-wife of wealthy Arab arms merchant Adnan Khashoggi, known for her tangled financial, matrimonial and other affairs, last married to her 20-year-old daughter's ex-boyfriend.

Their affair became public during a trial of three policemen, who were later convicted of trying to blackmail Soraya on an unrelated matter. On the stand, she admitted having an affair with a "prominent politician." She wrote his name down on a piece of paper, which was shown to the judge, and testified that her relationship with the man was "more than friendship" and was "common knowledge in m household."

As rumors flew about London as to whose name was on the slip of paper, Churchill authorized his lawyers to release a statement saying that "to avoid further speculation affecting other members of Parliament, Mr. Winston Churchill, MP, has instructed us to state that the name written down in recent criminal proceedings at Old Bailey, but not published, was that of Mr. Churchill."

Prime Minister Margaret Thatcher has declined to order an official investigation because, she said, "I am satisfied there has been no breach os security." Although Churchill presents himself in Parliament as an expert on defense matters, he has never held a government post or had access to military secrets. A few members of the opposition Labor Party have predictably called for his resignation from Parliament, but Conservative back-bencher Churchill intends to stay in the House of Commons.

Public revelation of the Churchill-Khashoggi romance, already well known in much of political and social London, nevertheless proved a popular diversion for weary Britons during the damp cold and darkness of winter. It provided a titillating, if short-lived soap opera for millions of tabloid newspaper readers and spicy cocktail gossip for their betters, who mostly were disturbed by well-born young Winston's choice of mistresses.

The affair was seen in British political circles as another example of some times immature judgment that may block Churchill, who is not yet 40, from a brilliant career.

The blond, blue-eyed son of Randolph and Pamela Churchill was born while his grandfather was prime minister, in 1940 at Chequers, where the visitors' book contains the entry, "4:20 a.m. Oct. 10 -- Winston." He was named for his grandfather at the insistence of his mother, herself the daughter of the 11th Baron Digby and now Mrs. Averell Harriman. Politics and world affairs were dinner table conversation at Chequer, and young Winston was inevitably drawn to them.

After a proper education at Eton and Oxford, he learned to fly, acquired his own small plane and went off barnstorming in Africa with a friend. They touched down in 40 countries, and Churchill wrote a book on the experience, "First Journey," which led to his working as a foreign correspondent for a number of British newspapers in Africa, Eastern Europe, the Middle East, Asia and the United States.

His name and engagingly earnest manner opened doors to national leaders and revolutionaries alike. When the dashing 27-year-old correspondent rushed off to cover the six-day Arab-Israeli war in 1967, his father called ahead to El Al, which held up a flight to Jerusalem until young Winston made it aboard. A friend of a friend of the family from World War II days put him in touch with Moshe Dayan.

Asked once about the advantages f his name, Churchill told a British journalist "I've never found it to be a liability except when it comes to being bonked over the head in Chicago."

He was covering the 1968 Democratic party convention and the clashes outside between police and anti-Vietnam War demonstrators when he naively asked one uncooperative member of Chicago's finest for his badge number. In turn, the policeman angrily demanded the young reporter's name.

"I told them," Churchill recalled. "That, of course, was a mistake."

Recognizing a wise guy when they saw one, the inquiring officer and a few friends frisked Churchill, roughed him up and tossed him over a 12-foot embankment."

His byline from the world's hot spots during the 1960s and his second book, "Six Day War" made him a hot property. He went on coast-to-coast lecture tours in the United States and Canada and made his first race for a seat in the House of Commons in 1967, losing by just 577 votes.

He was victorious in his second try at the age of 30 in 1970 in a Manchester constituency he still represents, flying there regularly from Satwick airport near his 12-acre estate, Broadmater House, in Sussex, south of London. He rose rapidly in Parliament to become the opposition spokesman on defense in 1976 under Thatcher, the new conservative Party Leader, making him a likely candidate for a cabinet post in a future conservative goverment.

Like Thatcher, Churchill is a stauch right-winger and anti-Soviet freedom fighter on defense and foreign policy. Knowledgeable observers say he sometimes seems obsesses with trying to make his name "as the scourge of the Russians," just as his grandfather stood firm against Nazi Germany.

Last year, Churchill made the mistake of rebelling against Thatcher's decision to support the then-Labour government in maintaining British economic sanctions against Ian Smith's former white minority government in Rhodesia. Rather than simply abstain from the parliamentary vote to continue sanctions, he defied Thatcher and the Conservative Party whips and voted to lift them. He also refused to resign his post as defense spokesman, the traditional step to take in such a conflict of conscience.

He then compounded his error by having himself photographed for the newspapers standing defiantly next to the statue of his grandfather across from the House of Commons in Parliament Square. Thatcher had no choice but to fire him. When she became prime minister last May, Churchill was conspicuously absent from her list of governmental appointments. c

Although he is acknowledged as a studious and unusually candid politician devoted to Parliament, Churchill was no longer taken quite so seriously when he repeatedly rose to speak from the green leather bench on which his grandfather had sat after he was no longer prime minister.

He remained in demand as a free lance journalist and lecturer and lived comfortably at Broadwater House and a London apartment with his wife and four children. He had married Mary Caroline "Minnie" d'Erlanger, daughter of a former BOAC chairman, in 1964. Their two daughters and two sons range in age from 4 to 14.

His wife said last week, in her only comment to the press, that he had already told her of his recent long affair with Soraya Khashoggi and that the Churchills are now "absolutely" happy."

Kashoggi, born Sandra Jarvis Daly 38 years ago in Leicester, the industrial midlands of England, net Saudi Arabian Adnan Kashoggi at the age of 19 in Paris after winning a trip there in a newspaper competition. She converted to Islam, changed her name to Soraya and married him two days before her 20th birthday in 1961.

In her billion-dollar U.S. alimony and support suit against Khashoggi, who divorced her in 1974, she claims she was instrumental in helping him become flamboyantly rich after they started out together in a two-room apartment in Riyadh, where he was a truck salesman. As their wealth grew, she groomed herself as an exotic beauty and became a photographer. Some of her most flattering photographs are self-portraits.

The Kashoggis had a home in fashionable Belgravia, where he became famous for his huge gambling losses in exclusive London casinos and she became known for her friendships with other men.

This time, Churchill may have shown good political judgment. His name was clearly bound to come out anyway, and he has been widely praised for owning up to it so quickly. Newspaper columnists and editiorial writers have belittled demands that he resign from Parliament and pointed out that sexual liaisons of all kinds are common among politicians.

Churchill paraded his smiling family past reporters and photographers from Broadwater House to London, where they attended a holiday season performance of "The King and I" with Yul Brynner at the London Palladium. He also took time out from the musical to show up in Parliament for an important vote.

He was greeted on his entrance and exit at the wood-paneled House of Commons chamber by back-slapping colleagues wishing him well. Churchill, who has been uncharacteristically unavailable for interviews, told waiting reporters only that he had "informed Mrs. Thatcher some weeks ago" and was "delighted" that she saw no reason to have his conduct investigated. Asked whether his revelation had caused a strain in his family, he answered, "Absolutely not."

The popular tabloids devoted much of their front pages the next morning to the Churchill family pictures. "The Happy Churchills TOGETHER," blazed the huge headlines on the front of The Sun, Britain's largest-selling national newspaper. "Winston and his wife share a loving look."

It wraped up the story with a happy ending just in time for Christ-Christmas.