LONDON — It has been widely denounced as one of the most divisive and racist public addresses made by a British politician in modern history.

Enoch Powell, a Conservative member of Parliament, gave what became known as the “Rivers of Blood” speech in 1968. In it, he attacked racial integration as a “ludicrous misconception” and “a dangerous delusion,” and predicted that “in 15 or 20 years’ time, the black man will have the whip hand over the white man.”

On Saturday night, the BBC will broadcast the entire text on radio for the first time — read by the actor Ian McDiarmid, who is famous for playing the “Star Wars” character Emperor Palpatine — as part of a program analyzing the speech and its impact 50 years after it was delivered.

The BBC’s decision has sparked widespread criticism and has been denounced as an “incitement to racial hatred” at a time when far-right nationalism, xenophobia and racism are on the rise in Britain and other parts of Europe.