Tonight, Trevor McDonald will be miked and powdered to read News at Ten for the final time. The news has yet to sink in. How will we cope? (Read Tennyson, suggests Trevor, helpfully)

At the start of the Woody Allen film Broadway Danny Rose, a bunch of old-timers sit round a table in New York's Carnegie Deli, swapping their favourite stories about the legendary theatrical agent Danny Rose. Behind the scenes at News at Ten these past few weeks, "Brandy" Reggie Bosanquet has inspired similar outpourings of nostalgia. Reggie smirking at the item about the firemen who rescued a cat from a tree and then backed their fire engine over it. Reggie's toupee. Reggie missing vital instructions from the gallery. Reggie getting pissed.

Actually, my own favourite News at Ten story has nothing to do with the late, great Reginald Bosanquet, newscaster from 1967 to 1979, but with the rather less colourful John Suchet. Twenty years ago, Suchet was dispatched to Iran to report on the American hostage crisis. Unhelpfully, Ayatollah Khomeini had banned foreign journalists from entering the country, so Suchet had a fake passport and a batch of business cards made up, describing him as a dealer in Persian carpets. His resourcefulness paid off. He got to Tehran, stayed for a month reporting the story, and returned to London, where he learned that the Ayatollah had, some weeks before, ordered the execution of all Persian carpet dealers for profiteering at the expense of the state.

And now the ayatollahs who run ITV have ordered the execution of News at Ten. Tonight, after 32 years, it bongs its last. From next Monday, Trevor McDonald is taking his bongs to the News at 6.30, which will make his final "And Finally..." at around 10.27 tonight almost unbearably poignant. Well, quite poignant, anyway.

Rather like the Iranians in 1979, ITN has issued a ban on outside journalists. The press will not be allowed to sit in on the valedictory News at Ten, and there's probably no point trying to get in posing as a carpet dealer. But on Tuesday night I was given a warm welcome at the grand ITN offices on Gray's Inn Road in central London, home of Channel 4 News and 5 News on Channel 5, as well as all the bulletins for ITV. This, when you think about it, is bizarre. As I have noted before, for the same news organisation to produce the highbrow Channel 4 News and its lowbrow counterpart on Channel 5 is tantamount to the same Mrs Gascoigne giving birth to both Bamber and Paul.

Anyway, at 8.08pm I was collected from the impressive ITN foyer by Trevor McDonald himself, who ushered me into his office and, slightly surreally, began reading to me from a book of Philip Larkin's collected poems. "It is these sunless afternoons I find/ Install you at my elbow like a bore," he said. I don't think he meant me.

McDonald is something of a poetry fiend. When we discussed the fuss generated by the controversial decision to chop News at Ten, he quoted Tennyson. "Faction seldom rises head," he said. Sorry? "It means that the English do not like change, are not given to revolution. So when something like News at Ten is moved, they are affronted. What do you mean, they say, by moving these certitudes from our lives?"

What indeed? As that old grump Gerald Kaufman has said, the passing of News at Ten - which in theory clears the schedules for four hours of lowbrow entertainment between news bulletins - "is a milestone in the dumbing- down of Britain." Not surprisingly, the chief executive of ITN, Stewart Purvis, disagrees.

"Ever since the phrase `dumbing down' was invented, people have been trying to find examples," he told me. "The fact is that with an early news programme at 6.30, and a late one at 11, we now have broadly the same schedule as most commercial networks round the world. You could say that News at Ten was a wonderful British anomaly and that would be true. It always was wonderfully peculiar."

Peculiar or not, ITV is shedding a powerful brand name. "Morse comes close, but I think you'll find that News at Ten has the biggest share of ABC1 viewers of any ITV programme," a former ITN hand told me. "Privately, a lot of people at ITN are still pretty upset about it going, but they will never say so publicly. They are all strictly on-message."

An on-message Trevor McDonald put it slightly differently. "We wouldn't want anyone else to appropriate our pain," he said. "We are the ones who've worked here for years. But we now have a series of new challenges. And ITV has invested enormously in the new current affairs programme, Tonight, which will be placed confidently in the middle of the schedules."

He was being characteristically bashful. The high-profile Thursday night programme is actually to be called Tonight With Trevor McDonald, representing the latest phase in his transition from mildly-admired newscaster to venerated TV superstar.

My theory is that the chief catalyst in this transformation was the Lenny Henry character, Trevor McDoughnut. McDonald roared with laughter at this. "I wouldn't disagree, though I usually tell Lenny that he owes me, not that I owe him. No, I think it has more to do with when I became the single anchor on News at Ten seven years ago."

Either way, McDonald is fantastically popular with Middle England, conveniently enabling people who would hate a black family to move in next door, to deny their racism to themselves. He acknowledged this. "But is it me or is it the power of this medium?" he asked, rhetorically. A bit of both, I said. He is not the best newscaster around - I treasure the day he said, "And now for the other day's news" rather than "And now for the day's other news" - but he is less headmasterly than Michael Buerk, more avuncular than Peter Sissons, and long may he bong, at 6.30 or whenever.

Besides, seeing him gliding around the News at Ten newsroom on Tuesday night was to see a man both at the top and on top of his profession. By 9.45 he was sitting at his desk having make-up applied. At 9.52 he was handed a piece of paper which read "Tottenham 3, Southampton 0". He was delighted. "I think I'll sing that," he said. McDonald is a Spurs fan. "Three-nil to the Tott-en-ham," he sang, tunelessly. A technical bod in the control room looked slightly nervous.

At 9.59, McDonald spoke calmly to the autocue operator. "Could you put capital Bs in beef-on-the-bone," he said. "And a comma after bone, please, would you mind awfully?" The "would you mind awfully?" reminded me of something an ITN insider once said to me, that McDonald, the lad from Trinidad, has basically reinvented himself as an upper-middle class English gentleman, fond of champagne and jolly big cigars. "I think Trevor thinks he's white," she said.

In many ways, this is grossly, almost slanderously unfair. Covering stories in apartheid-riven South Africa, for instance, he was frequently assumed to be the driver rather than the reporter, and recalls standing alongside a group of Afrikaaners he was about to interview while they discussed which restaurant they could take him to. "I did used to go back to my hotel room with a bottle of wine and burst into tears at the obscenity of that regime," he said.

But in a sense it is true, for McDonald has worked hard to avoid being professionally black. He encountered racism only once at ITN, years ago when someone accused him of being the organisation's token Afro-Caribbean. "It is true I was very worried that I would be relegated to black stories," he told me. "I said I would not do Brixton stories, and I almost begged to be sent to Ulster." In 1973 he was reporting on a riot in a Catholic area of Belfast when a woman, her face contorted with hatred, snarled at him: "You bloody English, why don't you go back where you belong?"

Until now, we have all known exactly where Trevor McDonald belongs. At the stroke of 10 on Tuesday night, the bongs sounded. "In Uganda today..." he began, concluding 26 minutes later with an "And finally..." about Lenny Henry receiving his OBE at Buckingham Palace. Disappointingly, there was no mention of Trevor McDoughnut. I think News at Ten missed a trick there. But after tonight, it no longer matters.