The annual seaside conference of Britain's opposition Labor Party climaxes Friday with the traditional rousing chorus of the Socialist anthem Red Flag, but the party's yearning for unity remains unfulfilled as a determined struggle for its political soul persists.

Labor appears trapped in procedural controversies over "left-wing" and "right-wing" supremacy, which enthrall delegates and the press while overshadowing broader areas of agreement on economic strategy and foreign policy. With a general election perhaps only a year away, the party's internal squabbles continue to weaken its bid to oust Prime Minister Margaret Thatcher's Conservative government.

Britain's economic crisis, with unemployment at its highest point in 50 years, provides a natural rallying cause for Labor's heavily working-class constituency. Yet, on present performance the party runs the risk of being outpolled not only by the Conservatives but also, possibly, by the alliance of Liberals and the new Social Democratic Party.

In four days of lengthy meetings thus far, the conference's most contentious dispute was waged over the authority to oust members of Militant Tendency, a Marxist faction that as a result achieved further notoriety for its views and celebrity for its spokesmen. Now the party's National Executive Committee -- its own election a matter of controversy as a result of some ballot fiddling -- must still decide who among Militant's supporters to expel.

Party officials sought to make the party seem less ideologically threatening to the British electorate by tossing out Militant. The avowedly radical faction publishes a newspaper, and eight parliamentary candidates chosen by local party organizations basically support the Militant line. In a vote at the conference, however, over a quarter of those tallied were opposed to plans to disqualify the group, which merely highlights the sympathy that it attracts in the party.

To an American eye, the conference superficially resembles a gathering of Democratic Party faithful, a sprawling, indecorous amalgam of activists groping for common policies under a banner of "Peace. Jobs. Freedom." Even the rundown seaside setting is reminiscent of old Atlantic City. It would be a mistake, however, to miss how far outside the conventional U.S. spectrum Labor operates.

In time-honored socialist style, speakers are called "comrade"; nationalization of key industries is a given objective; and, if there is a Soviet threat, it is not widely perceived here. On the nuclear issue alone, Labor's overwhelming majority for unilateral disarmament represents a fundamentally different sense of global priorities than that in the United States.

To a notable extent, while preparing for the future, the party's language echoes the past. Winding up his keynote peroration Tuesday, party leader Michael Foot invoked a 1930s Italian socialist, quoting a then contemporary German socialist as declaring: "Ours is the world!"

Foot, a thoughtful, literary figure of 69 with an unruly mane of white hair, is now cast as a centrist. In fact, he was for many years the party's guiding spirit of the left. But the ideology of the party has shifted in recent years, particularly since some of its former moderates opted to form the Social Democrats.

What is portrayed as Labor's right-wing are largely bloc votes from trade unions whereas the strength of the left is in grass-roots party groups. Their differences tend to be over how power within the party should be exercised and candidates selected. Whereas the last three conferences showed gains for the left, this year it was the right that gained a majority on the National Executive Committee.

While organizational battles continued in the corridors of the cavernous Winter Gardens, the conference did manage to blame unemployment squarely on the Thatcher government. It adopted resolutions calling for a program of reflation, job creation, renewed nationalization of major industry and import controls. Tony Benn, the leading voice of what is called the "hard left," won a standing ovation this morning by asserting that Labor's alternative to the present policies must be "control of capital, trade and investment."

The debate reflected little concern for higher productivity or quality control as an incentive to exports. The main vote today on worker conditions called for a 35-hour workweek, voluntary retirement at 60 with full pension and longer, more frequent vacations.

"We are on a moral crusade," said Benn in urging approval of economic resolutions. "We are fighting rotten, decaying values."