It's not real but it's very funny. This spoof phone-in is hosted by (fictional) Gary Bellamy, devised and produced by Charlie Higson and Paul Whitehouse who also appear, amid a glittering talent line-up which includes Amelia Bullmore, Felix Dexter and Adil Ray in the gloriously comic array of pretend callers. It's hard to go back to the real world of phone-ins after this, so perfectly does it capture their manic levels of non-communication.

The title should be rendered with inverted commas surrounding the "magnificent". Harry Enfield and Paul Whitehouse comment jovially upon an selection of extreme sports stars who have parlayed YouTube notoriety into celebrity. Yes, it's a clip show, if one populated by two talents as opposed to the standard phalanx of nobodies. Unlikely to become regarded as either comic's defining work, but it should almost by definition be at least intermittently compelling - as folly, hubris and people skateboarding into dustbins always are.

It's fair to say Harry Enfield and Paul Whitehouse have overmined the black-and-white movie seam in the latest series of Harry & Paul. But I'll happily forgive them that particular obsession. Because their gutting of Ricky Gervais last Sunday was as merciless as their On The Buses meets Sherlock sketch was inspired. If you're quick you might still catch them on iPlayer.

More old-style sniggers from Harry Enfield and Paul Whitehouse, the best of which come in the opening sketch in which the duo reimagine themselves as Ricky Gervais clones, with a "celebrity" appearance by UKIP leader Nigel Farage. It's a mixed bag, but a mirthful moment comes with Sherlock Holmes as seen through the lens of On the Buses.

No one would argue Harry Enfield and Paul Whitehouse are at the peak of their powers these days but boy, when they're on song they still deliver the laughs. Tonight there's a wonderful running gag involving characters firing AK-47s in the air to celebrate good news. It's simple, childish and great fun. The same can be said for this week's "When Life Was Simpler" sketch, where a clubbable 1930s gent decides to get married at the weekend. ("She looks nice, I'll marry her!" he says equably.) And I'm starting to love indecipherable trainer Podraig - another of Whitehouse's brilliant burbling flights of fancy.

I'm a bit torn over which is my favourite of the newer characters at BBC2's Harry & Paul. The Fifties East End typing-pool girls played in drag by Paul Whitehouse and Kevin Eldon have to be right up there, mainly because they sound like Russell Brand at his most annoyingly mockney.

But I also enjoy the 'When Life Was Simpler' films from the Fifties. The latest one featured a man being made Director-General of the BBC despite having no experience of or interest in television. Honestly. As if that would ever happen.

I was surprised to see the new series of Harry & Paul (Sunday, BBC Two) being aired at 10pm on a Sunday. Surely its natural home is a Friday evening, before or after Have I Got News for You? But after a moment's reflection, I appreciated what was going on. Sunday nights have become the most important ratings battlefield, with those who want something serious watching either Homeland on Channel 4 or Andrew Marr's History of the World on BBC One. Those who want cheering up with a bit of comedy head off for Downton Abbey on ITV1 - but where do they go for their laughs after that? ITV1 and BBC One head straight into the news. Channel 4 goes into comedy with the not very funny Friday Night Dinner. That leaves BBC Two.

The question is, are Harry Enfield and Paul Whitehouse still funny? Yes mostly, is the short answer, though their sketches are uneven. There were some old favourites included in the first episode, such as the intelligent and very posh surgeons, as well as the reactionary duffers in their gentleman's club discussing who in public life is and isn't "queer" (it was Michael Gove's turn in this one). These were unapologetic and well executed both.

But of the new material, some, such as a sketch involving two Irish-American cops in a bar, needed to be run through the typewriter again. While others, such as a black and white Strangers on a Train sketch, I felt I had seen before, Fifties parodies being their stock in trade. A sketch in which a posh racehorse trainer was talking in an unintelligible way to an Irish jockey, meanwhile, had shades of the Ted and Ralph sketches from The Fast Show. But that one can be forgiven if only because they managed to smuggle the "c" word into the stream of impenetrable verbiage in such a way that you were not sure you had really heard it. The most enjoyable of the new sketches was a subtitled parody of The Killing, which then bled into other sketches.

Their satire works best when their targets are generic and broad rather than specific. Their parodies of Question Time and Dragons' Den in this new series, for example, felt too in-jokey, like an office Christmas review in which you send up the bosses. The former would have worked just as well if the chairman wasn't supposed to be David Dimbleby.

The moronic questioner - "If the bankers, the bonuses, the bankers, the bonuses" - was spot on, however, though it didn't need David Dimbleby to spell out that he was a moron. "Man in the green jumper, do you have a clichéd thought for us?"

But the satire of Harry & Paul was never intended to be as sophisticated as that of Armando Iannucci, and there is room for both.

If you're a fan of, say, Keith Lemon or some such terrifyingly trendy comedian, your perspective on Harry Enfield and Paul Whitehouse is probably similar to the way Eric Sykes was viewed in his later years (Were they funny? Are they still alive?). Well, call me old-fashioned, but I love them. As they've got older, their comedy has got more ripe, more melancholy, more grumpy and, in the choicest sketches, funnier.

Apologies for the namedropping in this week's column, but I remember Whitehouse telling me he didn't realise The Fast Show gang were undergoing a collective mid-life crisis until he watched back the final instalments. Harry & Paul has picked up this theme, adding nice layers of bafflement and reactionary attitude. It's as if everything the pair have done in their careers has been building to the moment - oh blessed relief! - when they could affix ginormous codger's ears, sit in high-back leather armchairs and bluster to each other: "Would you say this one was... quare?"

For the new series they introduced the Minor Royals and some boasting, self-mythologising Irish New York cops (who get outdone by a boasting, self-mythologising Irish New York firefighter). They continued to spoof TV itself with send-ups of Question Time and The Killing - all highly promising. But I think my favourite character is still Marcus who sells useless tat at exorbitant prices to posh thickos.

If you're disappointed there's no Dragons' Den tonight, take comfort in Harry Enfield and Paul Whitehouse's version, which is almost as good. Other highlights in an undeniably patchy edition (the ongoing Canal Five sketch is a stinker) include Whitehouse's remarkable transformation into a physically accurate Larry David from Curb Your Enthusiasm and their take on a Mike Leigh film that has Morwenna Banks doing a superb impersonation of Alison Steadman in Abigail's Party.

Funniest sketch of the night award goes once again to the Minor Royals with Enfield politely asking a homeless man who's sleeping rough whether he's doing his Duke of Edinburgh.

I'm sure BBC2 has its reasons for burying Harry And Paul at 10pm on a Sunday night. But if Harry Enfield and Paul Whitehouse can keep up the opening episode's 70 per cent strike rate, I'm definitely in.

Their Question Time skit was spot on, especially the bit about the panel often including a 'comedian who wants to be taken seriously'. I'm presuming it was a reference to the likes of Steve Coogan and Jimmy Carr, but let's face it: the description could also apply to any number of MPs these days.