I met Ronnie Corbett once. It was during my time as a gossip columnist on this paper. I spotted him at a party and, somewhat starstruck, decided to approach and introduce myself. He was all right, I suppose, though not terribly polite. He didn't, he sniffed, read The Independent. More of a Telegraph man (must be the jokes). Anyway, he's 80 now, and BBC2 has devoted a few hours of scheduling to the occasion. First up was a rerun of The Two Ronnies Christmas Special from 1984, and then Being Ronnie Corbett, a fawning programme of dedications. We got Matt Lucas and David Walliams, Catherine Tate and Michael Palin, Miranda Hart, Rob Brydon, Stephen Merchant, and Bill Bailey. Even Bruce Forsyth put in an appearance. They all heaped praise on him, and deservedly so. After all, it wasn't them he was rude to at a party, was it? And he's jolly funny, or used to be, back in the day. Repeated clips of The Frost Report and The Two Ronnies were testimony to that. His more recent stuff, less so. That Extras sketch is great, of course - "a bit of whiz, you know? To blow away the cobwebs" - but, really, Ronnie, Little Britain? "I was just grateful to be included," was his explanation. And, to be honest, I believe him. This is a man whose raison d'être has been making people laugh; of course, he wants to keep up with the times. Why else would he agree to cuddle a half-naked Lucas in the least funny show on television?

Bruce Forsyth cooks the comedy wannabes

Final score. Bruce: 5 - Modern-day wannabes: 0.

The phrase "celebrity roast" sounds like either an inspired idea for a bonfire, a romantic date with a footballer and his friends or some nightmare series, no doubt soon to be commissioned, in which minor soap stars share their favourite recipes. In fact, it refers to the practice whereby a group of comedians takes turns putting down a well-known entertainer as well as each other.

That's what the roast became in America, where it was popularised by Frank Sinatra, Dean Martin and Sammy Davis Jr. Last week, we got the British version, A Comedy Roast (C4), in honour of, respectively, Bruce Forsyth, Sharon Osbourne and Chris Tarrant. For reasons of national morale, it doesn't do to dwell on the difference between those two sets of names.

However, the thinking appears to be that what the show lacks in personalities, it can make up for in vulgarities. Sometimes, that tactic worked under the caustic stewardship of Jimmy Carr, who looked as demonically thrilled as a class clown given permission to swear at his teachers. Carr was responsible for most of the moments of comedy that produced not a laugh, but a gasp, including a joke about Tiswas being the second biggest thing that Lenny Henry had ever been in.

More often, the coarseness was cover for an overreliance on the autocue. As much as he sometimes struggled with reading lines, Dean Martin was never known to resort to the c-word on US TV and nor, come to that, did anyone ever accuse Sinatra of mistaking breast milk for "man gravy". A dry roast this wasn't.

Yet the biggest failing was that no matter how crude the insults served by Jonathan Ross, Jack Dee and a variety of comedians, no one, including the guest of honour, had heard of, none could match the flame-grilled indignity of taking part in the show. A roast that was all sauce and nothing to savour.

And if we're looking to invent new words and phrases, how about "Crap as A Comedy Roast"? You'd use it to describe something that was as awkward and contrived and joyless as Jimmy Carr and chums spending an hour taking the p*** out of someone semi-famous sat opposite them on stage.

"Roasting" is an American tradition: being brutally but lovingly rounded upon by your peers while taking it all with benign grace - think: This is Your Life, You Stupid T***. The US TV version of this features some of the most staggeringly lewd, vicious punchlines I've ever heard, the enormous capacity of Pamela Anderson's vagina, for example, being a recurring theme on hers.

So what was in store for Bruce Forsyth, Sharon Osbourne and Chris Tarrant? Uncomfortable oddness, really. Jonathan Ross visibly rattled Brucey with some opening salvos: "He wasn't a pretty baby," he tells the audience, "but he did grow up to be a f***ing ugly adult." What else? Oh yeah: "When the dinosaurs died out, he was taken in for questioning." Arf! The weird thing was that most of the roasters were just typical gun-for-hire, Channel 4-type comedian fodder. Paddy McGuinness did a nervous Who Wants to be a Millionaire? skit on Tarrant, who looked so prickly throughout that you suspect Alan Partridge would have taken a roasting better. Jack Dee slagged everyone off and looked sadder than usual to be doing it. There was one quite funny joke about it being hard to believe the real Sharon Osbourne is here tonight, "because the real Sharon Osbourne is in a black bin bag round the back of a plastic surgeon's in LA!. And she took it all quite well, mainly because she just hooted like as sozzled nan the entire time.

Maybe everyone else loved it. It just seemed weirdly open and honest. I thought the whole point of being British is that we repress our true feelings, so that when they do pop out they're disguised, perhaps in the form of a witty joke or a song or a droll suicide note. Alternatively, we could just stick to slagging people off behind their backs so that we don't have to pretend to hug them in front of Jimmy Carr afterwards. I don't think A Comedy Roast suits us. If someone can work out a passive-aggressive equivalent, however, we may be in business.

The "roast" is an odd American phenomenon, a sort of testimonial showbiz party during which the guest of honour is mercilessly insulted by fellow celebrities. The tradition began at the Friars Club in New York and was televised as part of The Dean Martin Show in the 1970s, and more recently on Comedy Central. Now Channel 4 is bringing us a British version, Comedy Roast, with Bruce Forsyth as last night's inaugural dishonoree. Jimmy Carr, Jonathan Ross, Jon Culshaw and Jack Dee were among his genial tormentors - a "Who's Who of who was available," as Carr said. It looks as if they went through the Js of some publicist's email address book.

There's a problem with insulting Brucie: it's hard to get beyond his age. "When the dinosaurs died out he was taken in for questioning," said someone. "He's seen Halley's comet three times," said someone else. A lot of the jokes overlapped. Variations on "Nice to see you, to see you nice" abounded. Jonathan Ross said "fuck" a couple of times, but the whole thing lacked the sleazy exuberance of the original format (you can watch the Dean Martin ones on YouTube). Only Bruce himself seemed to catch the spirit of the thing. "That was funny," he shouted at Jack Dee. "I knew you'd make me laugh eventually."

My reviewer's DVD of the first of Channel 4's enterprising Comedy Roast was incomplete. It lacked a title sequence and, at the end, a caption read "CRAWLER CREDITS". But there were no crawlers to credit. Perhaps for the first time on British television the showbiz mafia came not to praise but to bury one of its godfathers. Still, as with the best man's speech, the tone is hard to get right. On The Larry Sanders Show the fictional chat show host was rendered suicidal by his friends' merciless "tributes". You don't want that. But you do want some of the barbs to hurt.

Bruce Forsyth's age was a subject of jokes back in his 1970s heyday and, even though, at 82, they are rather more acute now, they are still more affectionate than cruel. Jimmy Carr, the show's MC, led the way with them - Brucie was the first in his community to walk upright and use tools etc - but it was Jonathan Ross who took on Forsyth's real vulnerability: his marital record. Doing a passable Brucie impression, Ross mimicked him saying "I've told my wife we are working late, so we have ten minutes for a quickie, Anthea." Anthea Redfern, The Generation Game's lovely hostess, was to become, younger viewers may not know, the second, but not last, Mrs F.

He was not thanked for his efforts, even though Wilnelia Forsyth, herself, pointedly mentioned her husband's three wives. It was a deadly reminder of how lonely it is when you fall from favour as Ross, following the Andrew Sachs debacle, clearly has. Sean Lock was surprised Ross had turned up in person "because normally if you want to insult an elderly national treasure, you do it on the phone". That was good but it was Forsyth himself who did most damage. Eric Morecambe would have ripped into Ross ("I am sure he would," said Ross glumly). Ross was "all washed up and not even 50"£. The Ross-hating press has been accused of hyping Forsyth's attack but I think Ross had got to him, and for that he should be congratulated. A well-concealed side of Forsyth was briefly exposed.

Last Night's Television: Bruce Forsyth: A Comedy Roast

The point about a comedy roast - spectacularly missed by the newspapers who indignantly reported on Jonathan Ross's insulting remarks about Bruce Forsyth recently - is that the guest of honour is on the spit. An essentially American institution, in which showbiz entertainers gather for what the Scots would call a flyting - or an insult contest - the whole idea is that you let them have it with the best you've got. Offence and embarrassment don't have an invitation, since the only breach of good taste at such events would be to serve underarm because you thought the recipient couldn't handle anything tougher. What's really interesting about them, though - apart from the occasional pre-prepared aces - is that embarrassment is always lurking about there somewhere, waiting to pounce on the possibility that a friendly insult might have strayed just a little too close to a nerve. And in the first of Channel 4's Comedy Roast's it looked to me as if embarrassment was spending quite a lot of time near Jimmy Carr and Jonathan Ross.

It's a fate you wouldn't wish on your own worst enemy: Bruce Forsyth must have done something very bad in a former life to have his recent gruesome grilling by Piers Morgan, a man who insists on probing where no one wants to go, swiftly followed by the undercooked fawn-fest that was Bruce Forsyth: A Comedy Roast.

Starting with the dreaded words 'please welcome your host... Jimmy Carr!', a phrase guaranteed to have me instantly gagging (but not in a good way), C4's resident Smug MC, a ventriloquist's doll in human form, launched into his unique brand of makes-you-want-to-slap-him charm. 'A roast is like good-natured bullying,' he smirked. 'Good-natured in that it's happening to someone else, not you.' Unbelievably it was downhill from there, a gruesome selection of backslapping/stabbing blokes taking turns to out un-funny each other. Jonathan Ross started off with his tired effing and blinding routine, clearly miffed he wasn't talking about his favourite subject (himself). No, he was there to dishonour Bruczie, so what did Ross's rapier-like wit conjure up? No idea, it was instantly forgettable, other than setting up the night's weary theme: wow, Bruce Forsyth is, like, really old. He's done lots of dodgy gameshows. And he's got a chin. And a beautiful wife. Satire it wasn't.

Jimmy Hill's chin twin guffawed through gritted teeth throughout, taking it on the proverbial. But his lizard-like stare needed double-glazing to get through the kill-the-room combo of Bruno Tonioli and Arlene Phillips, whose contribution was up there with such classic double acts as Sam Fox and Mick Fleetwood and Rula Lenska and George Galloway for making you want to stab your eyes out.

All this crackling-free, toothless 'roast' proved was that the more people ho think they are funny there are in a room, the less likely you are to have a laugh. Only Sean Lock emerged with dignity intact but his best line - a dig about being surprised that Ross turned up in person instead of persecuting a national treasure by phone - was all over the trailers, so you'd heard it anyway. Next up it's Sharon Osbourne then Chris Tarrant - truly, C4, you are spoiling us.

Last Night's TV - Bruce Forsyth: A Comedy Roast

No turn was left unstoned, even Bruce's wife Wilnelia came in useful as a gag target for Manford, Carr et al, but she too managed to retain her dignity while all about her, juvenile jabbers were waving theirs goodbye. So will I be tuning in for any further helpings of 'roast'? That would be a no.

Review - Bruce Forsyth: A Comedy Roast

A couple of decades ago, TV royalty used to be rewarded for long service with a good-natured love-in on This Is Your Life. Not any more. This being the 21st century, the celebration has to be tempered with a smattering of sneering sarcasm and Jimmy Carr one-liners.