"Black's Britannica," documentary on minority life in Britain over the last 25 years, is televisions first look at the long-festering racial conflict in Britain. Especially for a black American audience and veterans of the American civil rights struggle, the discussions of police brutality, urban renewal and job rejection will be achingly familiar.

Speaking for the more than 2 million black and Asian immigrants are six black professionals and activists who draw a picture of a stagnant and oppressive society. Their view is that the immigrants moved quickly from a needed community of colonial subjects supporting the British economy, to a "new undercalss" deliberately discriminated against.

The one hour program, aired on Channel 26 at 8 p.m. tonight, begins with a mild statement from the originating station, WGBH, Boston announcing that the documentary does not include opposing views, but, the statement concludes, "We feel it is valuable."

"Blacks Britannica" is part of the "World" series of the Public Broadcasting Service which has examined issues such as apartheid in South Africa and the exploitative element of tourism in Third World countries. The series has been equally praised as enlightening and criticized as slated.

This particular program has received some advance attention. Claiming censorship, David Koff, the documentary producer, sued WGBH in an effort to stop the station from televising an edited version. WGBH countersued Koff, who planned to distribute his own version. One of the subjects, Colin Prescod, also sued the station. Earlier this week a Boston court denied the Koff and Prescod motions, and the edited version is the one being shown.

"Most of the material is the same," said Peter McGhee, program manager for public affairs at WGBH. "It has been restructured for logical, more chronological order."

Racism in Britain is a "continuing thread" in its history, said educator Ron Phillips, one of the professionals interviewed on the documentary. "Racism and the problem of race was imported to the U.S. from Britain,."

In the mid-1950s the West Indian residents of British colonies began migrating to Britain at the invitation of the government, but the doors began to close with the first of a series of immigration laws in 1962. As the British job market tightened, so did its generosity.

"If one weren't weary of talking about conspiracy, one would say there's a conspiracy against blacks," says Prescod, a sociologist, his voice heavy with irony. His view was supported by a spokesman for the Race Relations Institute, which has criticized the indequacy of the British government's anti-discrimination laws.

Like his American counterpart, black British youth has a high unemployment rate, estimated at 80 percent. In Britain the second generation of immigrants is refusing to accept factory jobs, is developing a political base and is switching from discontent to violence. There have been several bloody clashes with the National Front, an extreme political party dedicated to driving out immigrants from the Caribbean and South Asia.

In 1976 at a carnival celebration in London, black youths and the police clashed in the streets. According to the documentary, the police have stepped up the practice of arresting black youths on the suspicion of preparing to commit a crime. The practice is candidly discussed by teen-agers, and alarmed white lawyer and the police, who explain it as a preventive measure. No one seems to have a humane or logical solution.

Prescod quietly warns, "Britain is stuck with a rebellious black presence in its centers. And there is no way Britain can get out of this situation."