Armando Iannucci claims to be annoyed - although a tell-tale smile is playing across his lips. The mastermind behind such multi-award-winning comedy shows as The Thick of It, I'm Alan Partridge, Knowing Me, Knowing You, and The Day Today has just returned from a two-week holiday and is now horrified to discover that, as part of the BBC's latest reorganisation, he appears to have been "restructured".
"I go away for two weeks and the managers say, 'change everything'," splutters the leading comedy producer of his generation in mock outrage. "I now appear to be part of something called BBC Vision. What does that mean? I thought I was supposed to be making comedy shows. Still, at least we're not part of BBC People. I understand they're very nasty pieces of work." Warming to his theme, he storms to his computer and calls up an incomprehensible Venn diagram "explaining" the new BBC set-up. "When you see something like this, you think, 'I can't cope anymore!'"
Pointing at the baffling molecular structure on his screen, the producer continues: "I have no idea what those four helicopter-landing pads mean. Why do things like this happen? Does it give some people a way of filling in their days? By the way," he carries on, "do you think the consultants who drew these charts also draw charts about the structure of their own company, or do they get in consultants, too?
"In the end, of course," Iannucci deadpans, "this restructuring at the BBC will lead to a far stronger raft of programming across the digital map." Unable to keep a straight face any longer, he erupts with laughter.
This riff is typical of Iannucci - a naturally funny and irreverent man who is capable of locating comedy in the most seemingly banal areas. And yet, if truth be told, he actually has very little to complain about right now. After all, it is not every producer who is given an entire department to oversee, but here we are chatting in his spacious office, the nerve centre of "Arm's Arm", a wing of BBC Television Centre that is given over to the new comedy unit run by Iannucci. (You can tell it's his domain because all the walls in the surrounding corridors are plastered with stills from The Thick Of It).
His face may not be instantly familiar - a regular slot in The Observer does not give you the profile of a column in, say, Heat, and, although he has in the past fronted successful programmes such as BBC2's Friday and Saturday Night Armistices and The Armando Iannucci Shows and Gash on C4, and continues to present Radio 4's highly entertaining Charm Offensive, he now mostly confines his work to behind the camera.
It is safe to assume that the 42-year-old Iannucci, a slight, balding figure, is unlikely to be called up any time soon by the producers of I'm A Celebrity, Get Me Out of Here. For all that, the producer - who has helped launch the television careers of, among others, Steve Coogan, Chris Morris, Patrick Marber, Doon Mackichan, Rebecca Front and David Schneider - may be the single most influential person currently at work in British TV comedy.
He would be the first to admit that a year ago he endured a period of relative quiet in his career. "You're only as good as the project you're doing," sighs Iannucci, who is dressed in a white linen shirt, blue shorts and sandals with no socks. "So if you do a slightly bad one, you're slightly bad and have to start again.
"So I'm surprised by where I am now. Maybe after Alan Partridge, there was a question - 'is there anything else in his cupboard?' Perhaps some people thought that. Just 12 months ago, people were saying, 'who?"
No one is saying "who?" now, though. During the last 12 months, Iannucci has been in demand from producers of programmes as diverse as Imagine and Question Time. In addition, he has been the subject of those two great British institutions, Desert Island Discs and The South Bank Show - a sure-fire sign that you've made it.
But, genetically unable to take anything that seriously, he even turns that into a gag. "Being on those programmes implies that it's all downhill from now on," Iannucci laughs. "Once you've done The South Bank Show and Desert Island Discs, all that's left is ITV's An Audience With..."
Taking advantage of his new-found clout, Iannucci is fizzing with ideas about the future of comedy - many of which he laid out in a well-received series of lectures as the visiting professor of broadcast media at his alma mater, Oxford University, earlier this year.
He is eager, for instance, to de-stigmatise the words "mainstream comedy." "I'm very keen to persuade the people who write for Channel 4 and BBC 2 to write for BBC1 without thinking they have to muffle their comedy," enthuses the producer who grew up in Glasgow, went to a Jesuit school there, and now lives in Buckinghamshire with his wife and three children.
"'Mainstream' has come to mean something cuddly and safe. But there was nothing safe about Till Death Us Do Part, Steptoe and Son, Fawlty Towers or One Foot in the Grave. Those sitcoms were all about great writing for big audiences. I want to have a go at that. It has happened in mainstream drama. Russell T Davies writes bold, high-concept plots for Doctor Who. But we seem to think that comedy for big audiences has to be gentle and unchallenging. Just because you film a sitcom in front of a studio audience, it doesn't have to become twee or genteel."
To prove the point, Iannucci's unit is producing a number of pilots which he hopes will take flight. These include: Shhh, a comedy set in a library starring Morwenna Banks and Rebecca Front, who have co-written it with Arthur Mathews (Father Ted); Lab Rats, with Chris Addison, a "very cartoony" show about a university science laboratory featuring "lots of giant snails"; and a vehicle for Stewart Lee, the stand-up comedian and co-writer of Jerry Springer - The Opera.
But the programme which is currently tooting Iannucci's horn is Time Trumpet. This innovative, often near-the-knuckle, new series, which starts on BBC2 this Thursday, is a send-up of those I Love the 1970s-type shows that have spread across the schedules like a dose of STD. Time Trumpet is set in 2031, when raddled older versions of celebs such as Jamie Oliver, David Beckham, Charlotte Church, Ant and Dec, Tim Henman and Anne Robinson (played by suitably wrinkly actors) look back on the early 21st century.
By cleverly manipulating news footage (George W Bush singing "Imagine", anyone?) and mocking up various invented, yet all too plausible, scenarios (such as Tony Blair and Gordon Brown having a ferocious punch-up inside Number 10), Iannucci is able to use this imagined future to make satirical points about the actual present.
At one point, Iannucci's voiceover says of Tony Blair: "We look back on this madman and how he ended up 20 years later dementedly wandering around the bins of downtown Baghdad" - cut to a dishevelled, grey-haired "Blair" staggering about, muttering to himself, "move further down the bus. Have your money ready, please."
Iannucci explains that the "initial impetus behind Time Trumpet was watching those nostalgia shows and thinking, 'shut up!' Having - against my better judgment - been involved in one or two of those shows, I know what they're like.
"Ultimately, this format is a just a useful hook on which to hang jokes. In the same way as Spitting Image used puppets and Dead Ringers uses impressions, I thought, 'let's use older versions of real people on a nostalgia show to send up what's going on now'."
Ever since The Day Today burst on to screens 12 years ago, Iannucci has relished playing with the form of television. "Time Trumpet shows you can do anything with visuals now - and that may make viewers start to question what they take for real on television. They might see that even the news is an edit, a filter, someone's point of view applied to reality."
The producer's other abiding preoccupation is the extent to which politicians abuse language to further their own ends. In one episode of Time Trumpet, the celebs from 2031 reflect on the "war on terror" and remember that it reached such a pitch that terrorists were flying buildings into aeroplanes.
Is Iannucci concerned that viewers might be offended by such jokes? "I imagine people might be - given that 'terrorism' is one of those words you say and people are instantly offended.
"But I'm trying to make a point here about politicians turning terrorism into a concrete concept that we can have a war on. They use the fact that we're at war to change the law on anything they want. They might as well say, 'we're fighting a war on inflation - therefore, everyone has to do national service and can be detained for 90 days'."
Iannucci expands his thesis. "I'm interested in the abuse of argument. In the build-up to the war in Iraq, the Pentagon said, 'we have evidence of contact between Saddam Hussein and al-Qa'ida going back 10 years.' That phrase, 'going back 10 years' implies that it had been going on for 10 years. But what they actually had evidence of was a meeting at a very low level 10 years ago - and nothing since.
"It's like those posters outside West End theatres which read, 'amazing'. But if you go back to the original review, what the critic really said was, 'it's amazing that this play is on in the West End at all'. That sort of manipulation of language is now going on at an international level."
The producer is equally incensed by what he sees as Blair's flimsy reasons for going to war in Iraq. "I'm still angry about that," Iannucci asserts. "I thought, 'hang on, we're talking about people getting killed here'.
"If you enter a war, you've got to be absolutely sure about it - you can't just follow a gut instinct. Going in on a hunch is just not good enough. I'm not trying to drum up support for the trial of Tony Blair on manslaughter charges, but it's good to channel my anger creatively."
Iannucci has long been fascinated by politics - he hosted an all-night version of the Saturday Night Armistice on the election night of 1997 and has been a guest on Andrew Neil's This Week and The Daily Politics - and admits to being intrigued by the rise of the Tory leader, David Cameron.
"He's clearly read the book on spin that Tony Blair had in 1997 and said, 'can I have that?' But I think the bubble might burst for Cameron. Blair changed his party over three or four years, whereas Cameron is trying to do it overnight. You can't imagine the Tory faithful responding so well to that pace of change."
Iannucci's love of politics has also manifested itself in BBC2/BBC4's The Thick Of It, perhaps the best new sitcom of the last year. Devised and directed by Iannucci, the series won awards from both Bafta and the Royal Television Society.
Shot on wobbly, hand-held cameras, conducted at break-neck speed and semi-improvised by an inspired cast, the comedy provides a coruscating insight into the way politics is dominated by spin. Hugh Abbott (played by Chris Langham) is an incompetent minister who is utterly in thrall to the Prime Minister's tyrannical spin-doctor, Malcolm Tucker (a bravura display of shouting and swearing by Peter Capaldi).
Iannucci reckons that the show struck such a chord because, "people had already been building up a perception of the Government manipulating the media and vice versa, but up until that point, nothing had crystallised. Maybe The Thick of It just happened to come along at the right time."
But Iannucci thinks the show's appeal stretches beyond mere political anoraks. "Politics is about trying to work out what to say and what not to say. It's about the fear of being caught out. That's universal - it doesn't matter what realm you're in. Yes, Minister was basically about three blokes in the office and two of them trying to stop the other one doing what he wanted. That's a situation familiar to anyone who works in an office."
The producer is planning an hour-long special of The Thick of It, set behind the scenes in the Opposition party. Longer-term plans, however, are on hold until the outcome of Langham's trial is known - the actor has been charged with making indecent photographs of children.
"I'm hoping to do another series at the end of the year," Iannucci says, "but I've deliberately not wanted to decide anything till the whole legal process is finished. That's the only fair thing to do."
If there were to be a second series, however, Iannucci is brimful of ideas for it. "The first series was inspired by how politics was five years ago when Alistair Campbell was at his height. Now the notion of spin is much subtler. It's the spin of looking un-spun. Look at the Lib Dems, who say, 'the great thing about Ming Campbell is that he's Ming Campbell. There is no way we could have spun him - or he would have looked a lot better!'
"I don't want to be so obsessed with the media. I want to show how policies get compromised. In one episode, we could start with how one family is affected by a policy and trace it all the way back to the minister's desk."
So what has been the reaction of the real-life politicians to The Thick of It? "I've had no official response, but unofficially I heard from a junior minister that he had done exactly what we portrayed when the aides were making up a policy in the back of a car on the way to a press conference. I can't say who this minister was." What, is that protecting your sources and all that? "No, I can't say because I'd never heard of him and I can't remember his name!"
Iannucci has received no feedback from Campbell, either, although he has been told that Fiona Millar (Campbell's partner) likes it. "There again, Cherie Blair apparently liked Ian McEwan's Saturday [a novel about an anti-war demo in the run-up to the invasion of Iraq]. Don't you understand that it was your husband who caused it? Do you not get it?"
One programme that Iannucci will not be reviving in the near future is I'm Alan Partridge. Steve Coogan's brilliantly crass presenter first appeared 15 years ago in R4's On the Hour, one of Iannucci's first producing jobs after he gave up a PhD on Milton at Oxford University to pursue a career in comedy
There was talk last year of a movie in which Alan, left, got entangled with al-Qa'ida, but in the wake of the London bombings the idea was quietly dropped. "It was tempting to stay on and do more and more series of Alan," Iannucci muses, "but I'm glad now that we left it and moved on.
"That doesn't mean that at some point Alan won't re-emerge. I'd love to do something with Steve again, and at no point have we said, 'that's it'. Look at the faded celebs like Tony Blackburn getting a second chance in reality TV shows. I imagine Alan's agents have already been in discussion with the producers of Celebrity Colonic Irrigation."
What is remarkable about Iannucci is that, even after a decade and a half at the top, his comedy remains fresh and inventive. He has never fallen into the rut of repetitiveness that bedevils so many once-successful comedians. "I remember Stephen Fry and Harry Enfield talking about when you hit 40," Iannucci says, "and you catch yourself dressing up as a bishop for a sketch and think, 'am I too old still to be dressing up and putting on funny voices?' I don't feel that yet, but I am aware of it. I'd feel less inclined to do something like Saturday Night Armistice now - that's for people younger than me. But I still feel there's more to be done."
Unable to resist one last, self-deprecating gag, he adds: "But it is frightening when someone comes up to you and says, 'I loved I'm Alan Partridge, but I don't remember Knowing Me, Knowing You because I was only 10'. You see all these performers who look 12 and think, 'I've become a seedy old bloke who will soon be asked to appear in Last of the Summer Wine'. At least I hope I will!"
'Time Trumpet' starts on BBC2 on Thursday at 10pm