Twenty Twelve exploited the potency of deferred pleasure last night with the return of Sally, Ian's haplessly lovelorn PA, recruited by the perky Daniel after he was headhunted for Lord Coe's team. Her arrival in Ian's hospital room, in the midst of a cloud of self-deprecation and apology, was wonderfully touching. This was partly down to Olivia Colman, who can do more by lowering her gaze than many actors can do with their entire body. But it was also to the credit of John Morton's script, which sits very sharp satire on a foundation of beautifully understated character studies. Without the latter the former might get a bit thin. But with them it is irresistible. He can write a punchline too, one of which might serve as a useful slogan for the Home Office team currently dealing with security: "If we get this wrong we're in danger of running out of feet to shoot ourselves in."

As the Olympics loom in real life, so they do in this short third series about the fictional - but it's a close call - "deliverance" group behind the Games in Twenty Twelve, still the finest comedy this year. This week we're mired in meetings of the "catastrophisation committee". The straight-faced delivery of such too-believable abominations is one of the joys: those offscreen must have their fists in their mouths. Only two things scare me: when the actual Olympics are over, so will this be, which leaves in me the same conflicting emotions as someone desperately wanting to be rid of a massive toothache but knowing they'll miss the fun drugs. And the fact that writer John Morton is becoming - as real and fictional universes curve faster together - ever spookily, supernaturally more prescient.

In the opener to this series there's a desperate attempt to "re-brand" the problems everyone expects with transport. Not to solve the problems, of course, but to call them something else. There are too-late-in-the-day panics about security, when they've had five years to get it right. There is much hustling for post-Games power over both "sustainability" and "legacy", when it's quite clear no one quite gets the difference. In real life it was even worse; just read last week's papers. But Morton and co made this a while ago, and if he is a djinn and a seer, he's also a psychopomp: one of those ancient spirits whose job is to lead us benignly into hell.

Characters get ever better, and we'll miss them. Logistics manager Graham Hitchins somehow grows ever more gauche and unknowing with every episode. As the team argue over special lanes for VIPs, and special special lanes for Americans, he deadpans: "Yeah, but what happens if you want to have some sort of... baby, or heart attack."

Towering over all, technically, has been a masterful Hugh Bonneville as Ian, a very modern doomed English Everyman, surrounded by fools and too polite to say so. But main memories will be of Jessica Hynes as grotesque "head of branding" Siobhan Sharpe; apparently London PR people now regularly quote her imbecilities ("It's not arugula science, guys!"), some of them maybe even ironically. Though I don't know whether they'll stick with this week's "If we get bandwidth on this, you've got maple syrup on your waffle from the get-go: what's not to understand, guys?" A quiet aside from Nick, the refreshing Yorkshireman, dry as a stone dyke: "Well, you, basically." Terrific ensemble, and I'd put up with more of the Games toothache for more of this. Almost.

Comedy is all about timing, and so - with the Olympics a matter of weeks away - here come the final three episodes of John Morton's strangely underloved Twenty Twelve, a chance for the men and women of the Olympic Deliverance Commission to get ahead of the game, or, as head of deliverance Ian Fletcher (Hugh Bonneville) deadpans, "ahead of the Games".

It is 8 o'clock on Monday morning at the start of another busy week ("32 Days to Go") and our crack team has been assembled for a breakfast meeting. On the agenda, the post-Games plan for the stadium, security, and public transport. But first there are the pastry options (muffins, croissants, "those Portuguese custard tart things, I'm not sure what they're called ...") and, once that's settled, the endless order for "double-decaf skinny soy macchiatos".

The long-suffering Fletcher sits through it all. Perhaps he knows, as we do, that when the meeting does get under way, the air will be heated with words only because that's what people are supposed to do in meetings. "I should say," offers head of legacy Fi Healey, "that in sustainability terms we've always had the stadium down very clearly as a legacy commitment first rather than a sustainability issue second." Eh?

With its "catastrophisation feedback", "pre-conversationals" and "preliminals" gobbledegook, Twenty Twelve could be accused of being a one-joke wonder. But what a glorious joke it is. And while we've seen this sort of thing many times before (the aloof voiceover, the fly-on-the-wall camerawork, the tumbleweed script), there is something uniquely British about admitting that the people who run things are as incompetent as the likes of you and me. If The Thick of It is a savage Yes, Prime Minister for the age of spin, Twenty Twelve is Dad's Army scripted by Joseph Heller, and I for one will be sad to see it go.

The pick of the bunch - for one final week - remains John Morton's iron fist inside a velvet glove; pulverising management gibberish and lampooning jargon-spouting 'creatives' everywhere, for the viewing pleasure of those of us on Planet Normal. This week, following a cheeky jibe about 'difficulty raising funds for a proposed high-tech curtain wrap' for the Olympic Stadium (what could they possibly be referring to?), attention instead turns to the sponsors for the wrap around Anish Kapoor's Orbit Tower: a US condom firm. Can the Olympics be rebranded as 'a global sexual event'? Tremendous performances and pin-point satire (only a pained hip hop parody misses the target) ensure another splendidly entertaining half-hour of comedy.

The weekend's viewing: Twenty Twelve, Fri, BBC2

If we didn't have the Olympics, we wouldn't have John Morton's Twenty Twelve, a mock-documentary about a fictional Olympic Deliverance Committee. It didn't make a huge amount of noise when it originally came out on BBC4, but aficionados will already know it's one of the funniest things on television.

Delivering the Olympics is a job so insanely complicated, it should be beyond the remit of any mere mortal.

And the British Olympic Deliverance Committee is back to prove once again just how very fallible and human they can be.

Winner of the Best TV Sitcom in the British Comedy Awards, John Morton's mockumentary has finally been released from the scheduling ghetto of BBC4 and promoted to BBC2 for two new series before the real thing kicks off in July.

This week Algeria is threatening to boycott the Games because the all-purpose prayer centre in the Olympic Village doesn't have any of its walls facing Mecca.

For head of Deliverance Ian Fletcher (Hugh Bonneville) it's just one more PR nightmare to add to the towering pile of other PR nightmares in his in-tray that he really doesn't need.

Having just separated from his wife, he's also about to move into a new flat - which is a chance for his quietly superhuman PA Sally (Olivia Colman) to prove just how invaluable she can be.

Sally is secretly in love with Ian, of course. Just check out the look of pure jealously that flickers across her face for the briefest instant as an attractive new girl joins the team as Head Of Legacy.

Head of Sustainability Sally Hope (Amelia Bullmore) is not pleased to learn she'll be sharing an office either.

But she's not bothered about the Algerians.

Her only care is that 2012 will go down as the games that changed the way people dry their hands.

One of last year's biggest comedy success stories, this mockumentary, which won Best Sitcom at the 2011 British Comedy Awards and was given its own Sport Relief special, has been promoted to BBC Two for this second series. We return to the shambolic offices of the fictional Olympic Deliverance Committee, headed by pen-pusher Ian Fletcher (Hugh Bonneville). His signature torturous metaphors, delivered with earnest sincerity, provide much of the comedy - among tonight's gems are "Sustainability is the centre pole that keeps this whole tent up". Jessica Hynes also shines as Head of Brand Siobhan Sharpe, a Sloane Ranger who talks in a baffling text-speak. Tonight, Fletcher faces a publicity nightmare when Algeria threatens to boycott the Games because the Olympics' new multi-faith centre doesn't face Mecca.

John Morton's satire doesn't bite so much as lick playfully at viewers like a friendly labrador. This is largely Bonneville's show, his wonderfully Pooterish Fletcher showing off the actor's talents better than Downton Abbey. With the real Games about to begin, it's fun to imagine a similarly crazed paddling going on just below the surface at Olympics HQ.

This Olympic-themed mockumentary's screening in the stadium of BBC Two as opposed to the school athletics track of BBC Four, where it was first shown, magnifies its flaws. John Morton's script isn't ambitious enough to go for the laughs it could wring from the subject matter, despite the actors' best efforts. Tonight, the Olympic Deliverance Team, run by Ian Fletcher (Hugh Bonneville), recruits ex-athlete Dave Wellbeck (Darren Boyd) to tour schools inspiring youngsters, but it turns out he has all the dazzle of a frayed jock strap.

Finally on real TV, and one of those things whose slow-burn brilliance for once merits repeated repeats (though why the BBC earlier this year hid it away on BBC4 at something like midnight is still a mystery; doesn't it know when it's got Office-standard comedy?) is Twenty Twelve, John Morton's pre-Olympic spoof mockumentary which opened on BBC2 with a typically splendidly bright episode about a clock. An Olympic clock, of course. The proud chippy young northern artist won't explain quite how it works - "it's not snarking complicated". Except he doesn't say snarking, and it is in fact stupidly complicated. It's up to the fine Hugh Bonneville, head of "deliverance" for 2012, and Jessica Haynes as his memorable gobbledespeak PR to fail to work out how it works. "Look, does it count backwards in numbers or in time?" inquires anxious hapless Hugh of her. "Yeah, sure, OK. Well, either. I mean, both. Sensational!" Slowly, you realise there is a horological car-crash ahead. Every episode here is a subtle gem, getting way too close for comfort on the excruciations of political correctness, our modern failure to organise a cup of tea without a flowchart and the impossibility of getting athletes to say anything interesting, ever. It's on at a normal time now and you've no excuse for missing it. I'm going to record every one and play it as balm throughout the horrors that will be our real 2012.

The BBC4 comedy makes the move to BBC2. There will come a time soon, after the cost is tallied and the results examined, when the 2012 London Olympics will be no laughing matter. Until then, it's fair game. Writer-director John Morton previously helmed the great People Like Us, and here the tone is similar and the standard just as high. Set in the Olympic Delivery Committee, complete with dreadful logo, we meet the excellent cast - Hugh Bonneville, Olivia Coleman, Jessica Hynes, Vincent Franklin - as they prepare to relaunch their website. A terrific start.