There's a whole lot wrong with Steve Coogan's new live show, his first for ten years. Its ideas aren't fully developed, its structure is scrappy, and its star, at least on the third night of his three-month tour, is under-rehearsed.

So I hate to shower praise on something so palpably half-cocked. But, sorry, the character- comedy showcase Steve Coogan is Alan Partridge and Other Less Successful Characters offers some of the best laughs I've had all year. As Partridge in particular, his talent for portraying feisty failures is as glorious as ever.

In fact, it makes you wish he'd junk the others and just do a show about Alan, here reinventing himself, with typically monstrous mediocrity, as a motivational speaker. Alan's Forward Solutions, Rob Brydon's voiceover informs us, have been seen by “more than a tenth of a million people” - but this isn't a satire on self-help so much as another satire on Alan, who blunders his way obnoxiously through anecdotes, interviews and a great running gag with a computer slideshow.

Dealing ineptly with his angry sponsors, fondly remembering an encounter with Trevor Phillips - “he was receiving an award for least racist person, or something” - he then stages a drama about Thomas More, reinventing the wilfully inept Ernie Wise playlet with a wit that is hard to resist.

The Partridge section, which takes up the second half, is a mix of the familiar and the new - and, if the logic to the show-within-a-show doesn't bear looking at too closely, the gags come fast enough for you not to worry about it.

The first half is, as the title suggests, less successful. But, of the minor Coogans, only the anti-drugs lecture by ageing rocker Tommy Saxondale - a superb character in sore need of the right context - is a real dud. His grizzled superciliousness is almost incidental to the gags, whereas Nineties stand-bys Paul and Pauline Calf and hopeless stand-up Duncan Thicket at least reprise their shticks, even if they don't expand them much. Still, Pauline's sci-fi novel, in which Britain is ruled by dogs, is memorably odd, Paul's nods to Benny Hill are dubious but funny - “cutting-edge comedy,” he self-mocks - and Thicket's rows with his ventriloquist doll bring us into harsher, more interesting territory that Coogan drops too soon. But it's all played with a sure comic touch, even despite some early-days wobbles.

It's a shame there is nothing personal about Coogan until the encore, in which his tabloid notoriety - his “romps” with strippers, etc - are turned into a Mary Poppins-style number. “I read somewhere,” an Edwardian policeman tells Coogan, “that you're a bit of a c***.”

With more of an idea to motor it, this could have been a sensational show, rather than merely great fun. But though Coogan is not a warm performer, the second half reminds us he can be a stunning, merciless one. His show is half as good as it could be - and twice as entertaining as most other comedy shows this year.

Next show Wednesday, Royal Concert Hall, Northampton (0115-989 5555)

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