In the thick of a new satire: Peter Capaldi on his new foray into gentle comedy

Foul-mouthed Malcolm Tucker has allowed his creator to explore his range of talents on film, TV, and stage.

Peter Capaldi is having lunch with me in a chic North London gastro-pub when an eager fan approaches and asks him to autograph a piece of paper in the style of his most celebrated alter ego, the foul-mouthed spin doctor, Malcolm Tucker, from BBC2's acclaimed political satire, The Thick of It. The Scottish actor politely obliges by writing a message replete with asterisks, but still far too rude to be re-printed in a family newspaper.

Capaldi reveals that this happens a lot. He says: "People come up to me all the time and ask me to swear at them. So I say, 'f*** off', and they love it. That's what they're after." Such is the price of fame!

You will be very relieved to hear that in person Capaldi is a great deal more amiable than his most famous fictional character. The actor, who is currently earning enthusiastic reviews for his performance as the chief baddie, Professor Marcus, in the West End production of The Ladykillers, is as soft, sophisticated and smooth as Malcolm is shouty, sweary and seething.

Born in Glasgow, Capaldi demonstrated an embryonic flair for theatre by staging a puppet show at his primary school. At secondary school, St Ninian's High School in Kirkintilloch, he performed with a theatre troupe, The Antoine Players, before going on to train as a painter at the Glasgow School of Art. There Capaldi fronted a punk-rock band called Dreamboys. The drummer in that outfit was Craig Ferguson, who now hosts his own chat show, The Late Late Show, on US TV. Meanwhile, the bassist was Temple Clark, who has since carved out a successful career as a storyboard artist on movies such as Harry Potter and the Chamber of Secrets and The Golden Compass. While still at art school, in 1983, Capaldi landed his breakthrough role as an oil company employee called Danny opposite Burt Lancaster in Bill Forsyth's charming movie, Local Hero. Many years of solid TV work followed. Like so many other actors, Capaldi made his TV debut in Crown Court (in 1984), before going on to appear in various episodes of Minder, Poirot, and The Ruth Rendell Mysteries.

The actor gave many memorable performances – he was electric, for instance, as Vera Reynolds, a troubled transvestite in 1993's Prime Suspect 3, and moving as Rory, a ghostly uncle, in The Crow Road in 1996. But, in spite of some terrific work, he somehow he failed to break through to the next level

The game-changer was the moment in 2005 when Capaldi was cast as Malcolm in The Thick of It. Despite – or perhaps because of – Malcolm's spectacular furies, the 53-year-old would be the first to admit that the fictitious spin-doctor, whom he has played for the last seven years in both The Thick of It and the movie In the Loop, has put a rage-fuelled, expletive-laden rocket under his career. The role has won him gongs at both the Baftas and The British Comedy Awards.

"Malcolm has transformed my career," admits Capaldi, who is dressed today in a zip-up black top and black cords and has cultivated a Tintin-style quiff for his role in the play. "Suddenly I became someone capable of being evil or complex or Machiavellian. That opens up a whole new range of things for you. I wouldn't be doing The Ladykillers if it wasn't for Malcolm's brand of manipulation. The higher your profile, the more people want you."

And now Capaldi, who lives with his wife Elaine Collins (an actress who has appeared in Mrs Brown, Selling Hitler and Psychos) and their 18-year-old daughter Cissy in North London, is in demand to an almost ridiculous degree. In the past three years alone, he has starred in Torchwood, The Suspicions of Mr Whicher, Skins, Accused, The Nativity, Doctor Who, Field of Blood and The Devil's Whore (in which he gave a memorably effete King Charles I). It has also just been announced that he will take a leading role in the second series of BBC2's period newsroom drama, The Hour.

Capaldi, who won an Oscar in 1995 for making the short film, Franz Kafka's It's a Wonderful Life, has also made a name for himself as an accomplished director. Two years ago, he helmed the award-winning BBC4 comedy about a geriatric ward, Getting On.

And now for something completely different. Capaldi's career takes another unexpected twist, as he presents, writes and directs Cricklewood Greats, a spoof arts documentary. In this delightful, meticulously-made send-up of the self-indulgence of so much TV arts coverage, which goes out at 9pm on BBC4 on Sunday, the actor plays a terminally earnest film buff recounting the chequered history of the fictional Cricklewood Film Studios. He introduces clips from long forgotten (and entirely made-up) classic British movies such as Clog Capers of 1932, Florrie Drives a Lorry, Dr Jekyll and Matron Hyde and Woman-asaurus Rex, all lovingly directed by Capaldi. It is an area ripe for satirising.

The presenter is a dreamer given to waxing lyrical about vintage British films. His prose turns particularly purple when he remembers the timeless movies made at Cricklewood: "A dream can't be grasped," he rhapsodises. "It dances around us in the dark, like an usherette having a fit."

The documentary covers everything from such silent landmark movies as The Flying Pie and the arrival of the talkies with such rousing 1930s comedies as Dial F for Florrie, starring the relentlessly upbeat Florrie Fontaine (whose family were "so poor, they lived under a fish and chip shop") to such deathless 1970s schlock-horror films as The Devil's Chutney and Breasts of a Vampire and the Carry On-style cycle of Thumbs Up movies starring the ceaselessly perky Jenny Driscoll in a variety of saucy roles.

The presenter explains that Jenny came to the movies after leaving a job in a chippie: "She had just missed out on being Miss Isle of Dogs and had come second as Miss Jumbo Saveloy two years running."

After a ludicrously ambitious Terry Gilliam destroyed the studios in the early 1980s by accidentally flooding them with 40,000 gallons of water during the making of his ultimate folie de grandeur, Professor Hypochondria's Magical Odyssey, Cricklewood was bulldozed in 1984 to make way for a hardware superstore. As the presenter mournfully puts it: "A palace that echoed with romance and terror, laughter and delight was smashed to pieces. What spirits were unleashed that day? What angels shuddered?" Cricklewood Greats is a pitch-perfect parody of the pomposity of the British film industry. It is so spot-on that some reporters have apparently got the wrong end of the stick and think that Cricklewood Studios actually existed.

"I don't know whether to tell the journalists," says Capaldi, breaking into a slow, wry grin. "They come to me and say, 'we're doing a lot of research into Florrie Fontaine'. They think these are real forgotten figures of the British film industry." Which in itself is a compliment to the accuracy of the pastiche.

The documentary majors on the self-deception of the British film industry. Capaldi, who created many posters and drawings for Cricklewood Greats himself, reflects that, "the British film industry has always tried to sell itself as something rather sophisticated. It's almost as if it thinks it is by royal command. It has always tried to claim the high ground, not only over Hollywood but over the whole of humanity!

"It claims that it does things better, but in fact, in the 1930s, very popular, mainstream stars like George Formby and Gracie Fields powered the British film industry and bankrolled the more effete, fey epics made by people like Powell and Pressburger. I like the constant rise and fall of the British film industry. But above all I like the workhorses who kept going no matter what."

Capaldi, who apologises that he must leave straight after lunch to appear on Alan Titchmarsh's ITV1 afternoon chat show ("I'm living the dream!"), revels in the faded pomp of many British studios. A man who has celluloid running through his veins, he enthuses that, "I'd happily hang around those places for weeks – I don't need Indiana Jones to be filming there."

Cricklewood Greats effortlessly takes the rise out of the delusions of grandeur from which the British film industry has perennially suffered. Capaldi smiles: "It always makes me laugh that at some British studios, the signs proclaim 'international' in italics, as if to say, 'we are not just a corner of Slough here, folks, we're international'. But there is still a very parochial, 'Mrs Wiggins who runs the canteen', quality to the British film industry.

"The Hollywood image of the movie business is all about ambition and high achievers like James Cameron. But the British film industry is much more about men who wear cravats and work with model trains and hope another series of Thomas the Tank Engine will be commissioned. That's really what the British film industry is like. When it rains on a Tuesday at a British film studio and there is no Angelina Jolie movie to make and even My Family has gone, it can be a pretty grim place. But I love all that!"

In Cricklewood Greats, Capaldi is simultaneously celebrating and sending up the British film industry. He certainly has a great love for kitsch old movies. "I've been steeped in British films since I was a child," he smiles. "This is how old I am. When I was growing up in Glasgow, on a Sunday they'd have a double bill for one night only. I remember when I was 17 sneaking into Dracula AD 1972. It was the last gasp of Hammer movies, where Count Dracula, played by Christopher Lee, met his arch nemesis Van Helsing, played by Peter Cushing – but in swinging London! It was set in the London of coffee bars and miniskirts – you almost felt that Tommy Steele should come dancing down Carnaby Street.

"It was full of girls like Stephanie Beacham and Joanna Lumley, who were forced into low-cut tops – whatever happened to those girls? The film was made by men from the 1960s who got it all horribly wrong. But for all that, what's not to love about that movie? It must be ripe for remaking now!" I would certainly go and see Dracula 2012 AD – set, perhaps, at the London Olympics?

Later this year, Capaldi will return to the role that made him, the Mr Angry of No 10. In spite of his vicious tongue and "light the blue touch-paper and retire" temper, audiences seem to love Malcolm. The actor thinks this is because: "He's honest. Although he is able to talk about lying and give people strategies full of deception, he has a clear purpose, which is to keep his party in power. He sees that as a higher purpose, so in fact he's an idealist. That's why he would find it difficult to shift parties – unless of course his diaries hadn't sold well and he needed the money!"

Malcolm is thought by many to have been based on Tony Blair's spin-doctor, Alastair Campbell. Capaldi recently had the disconcerting experience of meeting Campbell at an awards ceremony. "What was he like? He was actually charming – which was my fear!" The actor smiles.

"I was very cross about that... I prefer to stay away from all politicians because charming you is what they do. They say: 'Would you come to this private thing? So-and-so will be there and you can meet them". I always say 'no', because I don't want to get too close to them, and I'm frightened that I will like them! Who wouldn't like to hang out with important people and feel important themselves? I'm sure that's what happens to politicians – they get seduced by that feeling of importance."

Even when it is off air, Armando Iannucci's satire remains highly topical. "It was very funny watching all that lobbying stuff last year," says Capaldi. "In the very first episode of The Thick of It, Malcolm sacks a minister because of the drip-drip effect of the press making the government look weak. I'm sure there will be tons and tons of material to work with for the new series."

A man who takes a keen interest in current affairs, Capaldi is turned off by the venality he sees in so many modern politicians. "It's very depressing," the actor sighs. "Lobbying is repellent. We are drawing back the veil on all this Thatcherite spivvery. All these men are hanging around in air-conditioned skyscrapers in Dubai trying to do deals, but how much money do these guys who already have Ferraris and yachts need? They're not doing it for our country. I hate it!"

Beginning to work himself up into the sort of enraged lather Malcolm might envy, Capaldi continues: "Politics is so full of ego and greed. I'm fed up with it all. I'm reaching the point where I say, 'this is hopeless'. Is this as good as it gets? All those millionaires sitting around the Cabinet table haven't experienced what it is like to have no safety net and to know that your parents can't bail you out. Poverty has a draining effect – it makes people weak and scared. I don't want to be told how to do things by these guys. They have no right. Is this the best we can manage in the 21st century?"

As well as once more dipping into the Dictionary of Baroque Swear Words as Malcolm and taking up his role as quirky head of news Randall Brown in The Hour, Capaldi may well be making anotherslice of Cricklewood Greats, as he has already been working on a possible sequel.

"During the 1960s, Cricklewood Studios would have been desperately trying to be cool by making all these terrible rock movies. And when it was in decline in the 1980s, the studios would have made rock videos and recorded awful concept albums.

"So I've been working on a rock'n'roll version of Cricklewood Greats about an old-style troubadour who ends up working there. I thought, 'what if you're a cool pop star and then suddenly you lose it and you start appearing on Sunday Night at the London Palladium and hitting Sooty with a shovel? Suddenly this musician is caught between rock'n'roll and variety. They've dressed him up as Marlon Brando figure, but he's too old and overweight and likeable to be cool. What have you got? 'Sorry, I am too charming to be a rebel!'" As much as anything, Cricklewood Greats is a touching meditation on what happens when a performer and fame part company.

"What happens to everyone?" asks Capaldi. "I love the whole idea of people who fall through the cracks. Any performer fears that whatever success you have achieved is very temporary and that at any moment you'll find yourself with nothing to do. Everyone likes to think they still have clout and are still some kind of glamorous person, but what are they really doing now? They're going on Alan Titchmarsh's chat show!"

'Cricklewood Greats' is on BBC4 at 9pm on Sunday. 'The Ladykillers' is at the Gielgud Theatre, London, until 14 April