Michael Foot, white-haired at age 69, slightly stooped, his gait more a shuffle than a stride, made his way through the weekly market in the center of this agricultural town, an unlikely venue for the Labor Party leader because Banbury is a time-honored Conservative stronghold.

"We're going to get a Labor victory," Foot exclaimed through a loudspeaker to the small and generally impassive crowd of lunchtime shoppers.

Then he visited a hospital geriatric ward, where the patients were too infirm to notice him, and an unemployment center that excluded the press--"a disaster," conceded an aide to the candidate.

Foot met with local Labor Party faithful who had somehow persuaded London headquarters that a visit here was worthwhile, even given his tight campaign schedule before voting June 9.

As Foot's two-car cavalcade drove off to the next stop, a truck driver and Labor supporter observed in what he plainly meant to be a compliment, "He's not as . . . shabby as you think he will be."

In his quest to be Britain's next prime minister, Foot has a serious image problem. After a long parliamentary career as guardian of Labor's left-wing principles, Foot was elevated to the party leadership in 1980.

The vain hope was that as a respected party elder, he could end Labor's ideological infighting--despite his own commitment to policies of unilateral nuclear disarmament, state-subsidized economic revival and withdrawal from the European Community.

Instead, he has become a symbol of Labor's continuing troubles, a well-meaning but ramshackle figure widely lampooned by cartoonists as "Worzel Gummidge," a scarecrow of children's storybook lore. Once described by friendly political pundits as Britain's natural party of government, Labor under Foot is struggling to whittle away at the commanding lead in opinion polls of Prime Minister Margaret Thatcher's Conservatives.

Labor has always been what the British call "a broad church" of a party, spanning militant Marxists and social democratic pragmatists like prime ministers Harold Wilson and James Callaghan in the l960s and 70s. Wilson holds the modern British record of having won four national elections.

But the party's traditional alliance of trade unionists, minorities and the white-collar middle class has been severely strained by the country's economic problems and the growing activism of left-wingers at the grass roots. In 1981, four leaders of the party's moderate ranks broke away and organized the Social Democratic Party, taking 28 Labor members of Parliament with them.

As a result, Labor's internal balance shifted even further to the left, eventually producing a 15,000-word party platform for this campaign that a weary senior party member on the right said was "the longest suicide note in history."

Were Britain to leave the EC, close U.S. bases, renounce its own nuclear force and inflate the economy with massive expenditures as promised, the impact on the Western world, let alone on Britain, would be considerable.

At this stage, the likelihood of all that happening remains remote. Because of the Social Democratic defections and a just-finished redrawing of parliamentary boundaries that favors Conservative areas, where populations are increasing, analysts say Labor would have to win 97 more seats than it did in 1979 to gain a majority in the House of Commons. That would require the biggest electoral shift in Britain since World War II.

With every opinion poll still showing a Conservative lead of from seven to 18 points, Foot's campaign would have some reason to seem forlorn. Here in Banbury, it was definitely floundering.

The only posters were a few small handbills. The prosperous local weekly published on the morning of his arrival contained not a word about him. Few residents knew he was coming until his car pulled up at the market and Foot stepped out.

He travels with only three aides and no security men, a humble touch that leaves him at the mercy of television cameras and photographers who swamp him and prevent most well-wishers--or hecklers--from getting near.

Foot turned up at the Horton General Hospital a half-hour early and the administrator could not be found for several minutes to greet him. So Foot waited in the hallway, working a small watch and chain as worry beads. Later, he said that nurses and hospital officials had complained that damaging cuts were made by the Conservatives in the National Health Service.

As it happens, the geriatric ward that Foot visited will be completely remodeled and upgraded as part of a $6 million government grant that Horton recently received, according to a hospital executive.

In all, Foot spent about four hours in Banbury, one of the longest stops in his campaign day. He was seen by a few hundred people, he talked to few and the spare reports in British media noted, as the Guardian did, the "cracks appearing in the Labor organization."

The evening was better. Foot was the main speaker at a Labor rally in the Oxford Town Hall, a short drive away. The auditorium and balcony were crowded, mainly with young people as befits a university community, and Foot got a standing ovation. His themes of disarmament and an end to mass unemployment were plainly popular.

As he often does, Foot used examples from the 1930s and '40s to illustrate some of his main points. So he attacked the Conservatives because in 1938 their successful parliamentary candidate in Oxford, now the 75-year-old Lord Hailsham, who is lord chancellor, supported the government's appeasement policy toward Adolf Hitler.

The Tory was "in effect licking Hitler's jackboots after he had tramped on Czechoslovakia," said Foot.

Retorting a few hours later, Lord Hailsham said, "The old boy has plainly lost his marbles. Poor old, dear old Worzel Gummidge. He is ranting. He is hysterical."

In the speech, Foot also adopted a virtually neutralist stance, extolled the wisdom of the nonaligned nations and criticized the superpowers with equal vigor. The last time Foot visited the United States was in 1954, when he went as a journalist to cover congressional hearings involving senator Joseph McCarthy.

While Foot keeps up a hectic six-day-a-week pace--his schedule indicates that he takes Sundays off--other Labor party spokesmen were also stumping the country. The most visible is Denis Healey, the deputy leader and the strongest figure among those remaining of the party's right wing.

Healey, 65, is a man of verve and a scathing tongue, but he has had to accept a party platform at odds with his past positions on such critical issues as whether Britain should have a nuclear force. Friends say he recognizes that this may well be his last hurrah in the top ranks of the party and is giving it his best.

If Labor loses, it is generally expected that Foot and Healey will step aside and a new generation of leaders will emerge after yet another struggle among the party factions. Foot, however, is undaunted. He has bet Prince Charles a bottle of claret, The Times of London reported, that Labor will win on June 9.