The Weekend's TV: Rivers of blood, BBC2<br/>Last Orders, BBC2

"He had put a match to a tinderbox," said Michael Heseltine about Enoch Powell's infamous "rivers of blood" speech. And the cliché raises a question. How sensible would it be to live in a tinderbox and pretend that there was no fire risk at all? That, in essence, was Powell's defence, one written into the speech itself. He wasn't setting the fire, he insisted. He was simply striking a match in the darkness, so that people could see how great the risk had become. But that he had incendiary ambitions in at least one regard was categorically established in Denys Blakeway's film about the speech and its aftermath. The son of a close friend of Powell's, a local newspaperman called Clement Jones, said that the politician had told his father that the speech would burst like a firework, leaving stars hanging in the sky. The friendship ended about two hours after the speech did, when Powell came to pick up his daughters and Jones and his wife got their first appalled sight of his text, including its unquestionably racist account of "charming, wide-grinning piccaninnies" harassing an elderly constituent and pushing excrement through her letter box.

Powell got his explosion, as he expected, one that blew him out of high political office, and has made him a martyr ever since for people who never utter the words "I'm not a racist..." without adding a "but...". Every time there is racial trouble in Britain, someone is likely to invoke Powell's name as a prophet ignored and indeed Blakeway began his film by presenting it, potentially at least, as a chastened reassessment: "Many are now asking, 'Was Enoch Powell right to predict disaster in his Rivers of Blood speech?'" he said, over footage of the London bombings. This struck me as tendentious, to say the least. Are "many" asking this? Or is it just that I'm cocooned by the very liberal consensus that BBC2's White season (of which Rivers of Blood is a part) sets out to disrupt, in giving a voice and visibility to the white working class who feel dispossessed by Britain's growing diversity.

The resulting film couldn't answer the question it posed with a yes/no answer, since Powell's speech itself altered the future he was looking into. But it did provide some useful historical context for the melodrama of Powell's rhetoric. His experiences in India just after partition and a visit to America in the aftermath of violent race riots there left him convinced that Britain was "busily engaged in heaping up its own funeral pyre". But the extremity of his speech, the mad raptor's glare with which he delivered it, and the white bigotry that it enfranchised, caused such a flinch of reaction on the part of mainstream politicians that he provoked the exact opposite of what he wanted: not much in the way of further debate, and the decision that multiculturalism was the way to go, a state-sponsored endorsement of ethnic difference that sadly never got round to a robust definition of national sameness. Powell was right in only one sense: the subject needed talking about. But the fact that he started the debate in such an ugly and vainglorious manner didn't avert the dangers, it aggravated them.

The White season began on Friday night with Last Orders, an early and, I hope, unbeatable candidate for Most Depressing Documentary of 2008. A study of a white working men's club in Wibsey, a suburb of Bradford, it was made by an American documentarist, Henry Singer, who approached his subject much as if he'd been sent up the Orinoco in a dug-out canoe. He was touched by the warmth of his welcome and troubled at the way in which this unknown tribe's traditions were being eroded and destroyed by the encroachments of modernity.

The film's placing as part of the White season suggested that this had something to do with Bradford's changing population, and certainly Singer had no problems finding people who were prepared to blame all their woes on the city's Asian residents. But the truth is that Wibsey Working Men's Club is dying on its arse because the people who run it haven't had a fresh idea for about 20 years. It was a portrait of an institution largely glued together by stubborn habit and cheap alcohol, and since they now sell that glue even cheaper at the pub down the road, it's not surprising that it is beginning to fall apart. These weren't bad people (we really didn't need the plucked harp strings to tell us that) and they may be right in feeling that their own ethnicity is the only one that doesn't count. But in their glum and rancorous self-pity, they did not make a great case for themselves. The season is intended to shine a spotlight on a forgotten section of society. This film reminded you that sometimes shadows are more flattering.