Peter Capaldi swears by his signature role

Foul-mouthed Malcolm Tucker has allowed his creator to explore his talents on film, TV and stage. James Rampton hears about a new foray into gentle comedy

Red terror: 'People come up to me all the time and ask me to swear at them. So I say, 'f*** off', and they love it', says Capaldi (Rex Features)

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 BBC 2'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, he 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 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. Capaldi made his TV debut in Crown Court (1984), before appearing 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 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 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, winning him gongs at both the Baftas and The British Comedy Awards.

"Malcolm has transformed my career," admits Capaldi. "Suddenly I became someone capable of being evil or complex or Machiavellian. That opens a whole 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."

Capaldi, who lives with his wife Elaine Collins and their 18-year-old daughter, Cissy, in north London, is now 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. It has just been announced he will take a leading role in the second series of BBC 2'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, send-up of the self-indulgence of so much TV arts coverage, which goes out 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 (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 given to waxing lyrical about vintage British films. "A dream can't be grasped," he rhapsodises. "It dances around us in the dark, like an usherette having a fit."

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 Cricklewood Studios actually existed. "I don't know whether to tell them," says Capaldi, breaking into a slow, wry grin. "They think these are real forgotten figures of the British film industry."

Cricklewood Greats is on BBC 4 at 9pm, Sunday. 'The Ladykillers' is at the Gielgud Theatre, London, until 14 April