The comedy "roast" is a US showbiz institution where "roastmasters" pay mocking tribute to a well-loved star. Now Channel 4 is introducing the tradition here. Jimmy Carr compères and the first subject is Bruce Forsyth. His wife, colleagues and comedians including Barry Cryer queue up to take pot shots at his career, golfing ability and age. A consummate pro, Forsyth takes it all on that unmistakeable chin.

Although it might not sound it, a roast is the ultimate honour for any entertainer. First started at the New York Friars' Club in the 1920s and made famous by Dean Martin on his TV show in the 1960s and 1970s, a roast involves you sitting in a room with your friends, family and colleagues as they mercilessly take the mickey out of you - goodnatured bullying, as the host Jimmy Carr calls it. There are three roasts this week - don't miss Sharon Osbourne's on Thursday and Chris Tarrant on Friday - but first up is Mr Showbusiness himself, Bruce Forsyth. Lining up to pay mocking tribute are Jack Dee, Jason Manford, Bruno Tonioli, Arlene Phillips, Jon Culshaw, Barry Cryer and, best of all, Jonathan Ross. It may be sycophantic, but there are still some hilarious moments.

Channel 4 has imported the American comedy tradition of "roasting" a much-loved star with a series of cruel tributes. It's like watching a sequence of well-honed Best Man's speeches, delivered to an audience of eager showbiz folk in the kind of chandeliered room usually kept for awards ceremonies. Starting with Bruce Forsyth as the victim means a range of open goals to aim at, the main one being Brucie's age. "Many say that a knighthood is long overdue," observes host Jimmy Carr. "After all, so many of his contemporaries have been honoured. [Pause] Lancelot, Galahad, Percival..." There are quips about his golf handicap, his love of tea, his many catchphrases, his much younger wife, while Brucie himself wheezes with obliging laughter on the sidelines. And with three standing ovations, didn't he do well?

Unlike the US version of this show, which can be shockingly vicious and unpleasant (see Joan Rivers's on Monday), there's something rather comforting about Channel 4's effort, which sees tribute paid to Bruce Forsyth through mockery. Despite host Jimmy Carr giving off his usual warmth (reptile in outdoor bath, mid-Siberian winter), it's like watching a series of best man's speeches.

Jonathan Ross, Jack Dee and Barry Cryer all step up to wheel out jokes about how old Brucie is, how rubbish his early career was and how young his wife is. It does sound like irritating vieux chapeau - but it's done with enough classy lines to pass the time. In a comforting way.

For fans of excruciatingly painful television, don't miss Channel 4's Comedy Roasts in which Bruce Forsyth, Sharon Osbourne and Chris Tarrant are ritually insulted by visibly uncomfortable guests including Jonathan Ross, Sean Lock and Jack Dee. A longstanding American showbiz tradition, these British attempts are stilted and embarrassing. The Osbourne edition in particular is like a glimpse into Hell.

Ross slams Forsyth in outrageous TV comedy show attack

Jonathan Ross wound up Bruce Forsyth in an outrageous TV comedy show attack and scoffed: "You're f***ing ugly."

Jonathan Ross taunts Bruce Forsyth in new comedy show

Jonathan Ross is to insult Bruce Forsyth in a new TV comedy programme, telling him he's "------- ugly" and has "done a lot of ----" in his career.

I am not one to take against a garrulous homosexual - they constitute the greater part of my social and cultural diet - but the opening episode of Alan Carr: Chatty Man was the nearest I've ever come to shouting: "Just shut up, you rambling poof!"

While there has been amazing progress over the past ten years in making this country less homophobic (Graham Norton getting Eurovision, bisexuals on Doctor Who), the dark reality is that that many people have merely swapped homophobia for "finding gays cute".

I attended an advance fan-screening of Torchwood last week, and every piece of dialogue between Captain Jack and his boyfriend was greeted with knowing, slightly hysterical laughter from the audience - as if everything that the characters were saying was high-camp, bitchy banter. In actuality, a great deal of it wasn't, and some of it was outright sombre - yet it was all drowned out by Pavlovian giggling at the "cute queer couple having a bitch-fight".

If we really are reducing gayness to camp, in terms of social progress, it's going to be as useful as supporting sexual equality - but only so long as all the women are giggly and have big tits.

As a camp man at a crucial moment in his career, then, Carr has some mighty socio-sexual-political currents to swim against. Alas, to the disappointment of any watching recruitment officers at Stonewall, Carr's new chat show consists of little more than an hour of pointing at things - Bruce Forsyth, pictures of people from Big Brother, his own set - and squealing. It makes Mr Humphries from Are You Being Served? look like Harvey Milk.

With an hour of airtime to fill, without Justin Lee Collins, Carr appears not to generate any actual material - he just relies on mannerisms. The third line of his opening monologue is on Britney Spears: "She sings like she's talking through the intercom at a drive-thru McDonalds." Unfortunately, the line also appeared in a Mirror interview with Carr, printed on the same day - a pretty damning index of his productivity. The conversational topics for his first guest, Bruce Forsyth, were: how big Bruce's chin is, how old Bruce is, whether Forsyth knows who will be on the next series of Strictly Come Dancing? (no), and how old Forsyth is again. Forsyth seemed exasperated by the end - like an old, greying horse being harassed by a tiny Jack Russell.

Most damningly of all, the audience laughed at everything Carr said - like a previously unknown experiment involving Pavlov giving his dog a biscuit every time Larry Grayson said, "Shut that door".

How come we hear about Katie and Peter splitting up but not a word about Alan and Justin Lee Spaniel going their separate ways? Yes, things looked dodgy when Justin popped up with his own ITV2 chat show, but there was always hope they'd reunite. Sadly, Alan will be all alone when he speaks to Lord Bruce Forsyth, Heather Graham and Grant Mitchell, but that won't prevent the camp host talking the hind legs off a donkey sanctuary.

The comedian Alan Carr is certain to be a distinctive chat show host, each week offering what the programme-makers call "a good old natter with three celebrity guests from the showbiz world". No surprise appearance from Barack Obama, then. His guests tonight are Bruce Forsyth, the US actress Heather Graham (Scrubs, The Spy Who Shagged Me) and Ross Kemp, whose documentary series In Search of Pirates on Sky1 has become one of the highlights of the week's viewing. The Pet Shop Boys will close the show with a performance of their latest single, Did You See Me Coming?