Suits you sir: Bill Nighy talks politics and sartorial style

Few men wear a suit as well as Bill Nighy. But then, few men wear a suit as frequently as Bill Nighy. He wears them onscreen, he wears them onstage, and he wears them for interviews, as I learn upon entering the small, generic hotel room in which we're due to spend an hour alone together. "I always want to wear a suit, and I nearly always do," he says. "I'm a fetishist about what they used to call 'a decent lounge suit'. I sort of want to wear the same dark blue suit every day, maybe with a different shirt. My range of enthusiasm is pretty narrow; I occasionally take a break into dark grey, possibly a stripe."

Today's suit is, I'd venture, charcoal verging on black. It's from Zegna, "a superior brand" whose name Nighy kindly spells for me, explaining that he owns several of their suits, each cut identically to his specifications (though in mildly varying fabrics). He also has suits from John Pearse in Soho, and from third-generation tailor Ritchie Charlton, of Hayward in Mayfair. He doesn't have any suits from Savile Row, although he could probably afford them these days.

When he first fell in love with suits, he couldn't even afford one from M&S. His friend John worked at the now-defunct high-street tailors Dunn & Co when they were 18 and, "because he worked there, John got a discount. He was a mod, and he had seven suits: one for every day of the week. He wore a three-piece and a coxcomb hairdo and he looked very cool. That, for me, was the Holy Grail."

As a young actor, Nighy's wardrobe was limited to dark blue jackets that he picked up in charity shops, paired with Levi 501s, "probably a pair of Ravel loafers, and a Ben Sherman shirt – or, if I had a few quid, a John Smedley polo shirt. I was an early pioneer of that look in the days when girls would say, 'Are you really going to wear that?', because you were supposed to wear some sort of appalling silk paisley shirt with three buttons undone. I would seriously have to kill myself if I wore that. I never thought my body worthy of silk. You have to have a pretty marvellous top half to get away with draping it in silk."

He would also, he claims, "have to kill [him]self" if he popped his suit collar, or rolled up its sleeves, as was fashionable for a time in the 1980s. "Everybody did it," he complains. "You had to be in rooms where every other guy in the room was doing it. It's something people who didn't like clothes did." By contrast, he admires a man with a pocket square: "but I try it and I never get out of the house. I never feel like a bloke who can wear a hankie in my pocket". He's uncomfortable wearing belts, because they interrupt the flow of a suit: "One of the things about being able to have suits made is that you can make those decisions: to have ties at the side of the trouser instead of a belt, or to have a single vent, when the whole world tells you that you shouldn't."

It's a combination of truth and self-perpetuating myth that Nighy chooses his parts based on the likelihood that he'll get to wear a suit in character. "If I'm appearing in public I want to look my best," he says. "For an actor to say that is, of course, ludicrous." Yet even Billy Mack, the addled rocker who made him globally famous in Love, Actually, wore a dark suit to perform his seasonal hit "Christmas Is All Around". Nighy, now 62, does a fine line in thwarted, retirement-ready civil servants with spectacularly middle-English names – Johnny Worricker of Page Eight; Sir Bernard Pellegrin of The Constant Gardener – all of whom are sartorially immaculate, whatever their other failings.

The latest of these is Douglas Ainslie, unlikely romantic protagonist of The Best Exotic Marigold Hotel, who has sunk his civil service pension into his daughter's ill-advised internet venture, leaving him and his disgruntled wife Jean (Penelope Wilton) without a nest egg. Rather than settle for a pokey new-build in the suburbs, the couple decamp to a glamorous retirement home in India, accompanied by five more of Britain's greatest Actors Of A Certain Age: Dame Judi Dench, Dame Maggie Smith, Tom Wilkinson OBE, Ronald Pickup and Celia Imrie. When they arrive, they find the Best Exotic Marigold Hotel to be rather less glamorous than advertised. Most of them fall for their corner of the subcontinent, none the less. The film is directed by John Madden, of Shakespeare in Love fame, and adapted from a novel by Deborah Moggach, who also wrote Tulip Fever. In short, your mum will adore it.

Nighy has known the majority of his co-stars for most of his working life. He was at drama school with Imrie, has already played Wilton's husband once before, and been friends with Wilkinson for a quarter-century. He took the role, he says, for the chance to work with Dench for the fourth or fifth time. The two had one crucial scene, however, which he dreaded filming: not only did he have to ride a motorcycle for the first time – with Dame Judi riding pillion – but he also had to wear a flowery silk shirt in the style he abhors, with at least two buttons undone. "It was a very big deal," he admits. "That shirt was a compromise between the brilliant costume designer and my better judgement. I find it hard to relax around any man who's got the second button on his shirt undone. But they persuaded me to do it, to make it look as if I was wild and free and had embraced India."

The motorcycle was an equally hair-raising prospect. Nighy was brought up above his father's garage in Caterham, Surrey, where he was born in 1949. The workshop was next door, the petrol pumps just beyond the porch, yet he was never a natural driver. "I became a legend of bad driving," he says. "I could never pay attention for long enough. I used to drift into the back of people. My father gave me a lovely car to congratulate me when I passed my test, a Ford Prefect that he'd driven for years without incident. Within weeks, I got the bumper stuck in a chain-link fence and took half the back of the car off as I pulled away. Then my brother gave me a car; I did wonder what the little red light on the dash meant, but I didn't realise that it involved me actually doing anything [such as putting oil in the engine], until it blew up in the fast lane.

"I protected Dame Judi from this information before shooting the motorcycle scene, but I would wake up every morning dreading it. If you kill Judi Dench, you can't go home. You could accidentally kill the Queen and sneak back into the country, probably. But kill Judi Dench and you'd be overseas for the rest of your natural life."

Acting was not Nighy's first choice of profession. His teenage heroes were Hemingway, Fitzgerald, Ford Madox Ford and Bob Dylan. When, at 16, he left the John Fisher School, a Catholic grammar in Purley, he wanted to be a writer. Hemingway had been a cub reporter at the Toronto Star; Nighy tried the Croydon Advertiser, whose editor told him to go away and get some more O-Levels.

"I went to the National Youth Employment Agency with my mum, and when the bloke with the big book of jobs asked me what I wanted to do, I told him I wanted to be an author. My mum pressed her foot down on mine really hard. But the bloke got me a job as a messenger boy at The Field magazine in Stratton Street, a great job if you came from a small town. I used to eat my sandwiches in Berkeley Square and wave at all the Rolls-Royces. Eventually the proprietor, Sir Geoffrey Harmsworth, said 'If you learn shorthand and typing, we'll put you in the sub-editors' office'. Of course, rather than doing that, I ran away to Paris to write the Great English Short Story." Finally, after he'd failed to produce any such thing, a girlfriend persuaded him to apply instead to the Guildford School of Acting.

Nighy's career is exceptional, if only because he achieved fame so late. He was successful for some time, but few people would have recognised him in the street until 2003/4, when, aged 54, he won a film Bafta for Billy Mack in Love, Actually, and a TV Bafta for Cameron Foster, the charismatic newspaper editor in State of Play. (After that performance, several journalists wrote asking whether they could come and work for him.)

"It's probably healthier to find fame later in life," he suggests. "But, like most actors, I spent a lot of time worried about money. It was all right when I was single. But when you have responsibilities, it's harder. When you have a family, or even when you're just seeing a girl, it's difficult to be skint. I could probably have lived without some of those times. I wasn't starving; I had a weekly wage, and I was working with David Hare and Harold Pinter and Tom Stoppard and Judi Dench and Anthony Hopkins. But when I started to get recognised in the street, I simply viewed it in terms of money: when you're skint and people come up to congratulate you for something they've seen you in, there's a strong temptation to say, 'You couldn't see your way to lending me a £20 note, could you?'."

His route to success was also unconventional for such a respected British stage actor, in that he was never much interested in performing Shakespeare – and has only done so professionally twice: Lucentio in The Taming of the Shrew at the Chester Gateway Theatre in the 1970s, and Edgar in King Lear at the National Theatre in the 1980s. "I retired from Shakespeare in the bathroom one day when I was about 48," he explains. Yes, he found the technical challenges of the verse tedious, but he also hated the outfits. He has a much-repeated riff about how uncomfortable he feels in pantaloons (it has become a sort of public relations joke, he says, "but it's actually not untrue"), and he still suffers from nightmares about Edgar's requisite near-nakedness. "I turned up to Lear rehearsals in a loincloth," he recalls, "and was urged to put my clothes back on... in front of several women."

He prefers to operate within a contemporary, middle-class context, playing a variety of "violently constrained Englishmen". It's a policy that has allowed him to work consistently with some of the great writers of the age, such as Stephen Poliakoff, Richard Curtis and David Hare – with whom he has been collaborating since 1980. Hare is presently writing two sequels to his TV film, Page Eight, in which Nighy played ageing spy Johnny Worricker. The new films go into production later this year. "David calls them Page Nine and Page 10 or, sometimes, The Worricker Conundrum and The Worricker Ultimatum."

Nighy's recent films with Hare and Curtis have tapped into a strain of anti-war and anti-poverty activism. ("I've never felt much like an activist," says Nighy, "I haven't got the right trousers.") After he starred as Lawrence, another thwarted civil servant, in Curtis's G8/Make Poverty History drama The Girl in the Café in 2005, he was approached by Oxfam, and now regularly visits the G8 on the charity's behalf, to have cameras pointed at him, and to thus ensure "that the plight of the poor is a live issue on the agenda". At the start of 2010, he began working with the NGO campaign for a Robin Hood Tax on financial transactions. For an amateur, he seems to know his economic onions. "The tax met with howls of derision in the early days, but when you hear that Merkel and Sarkozy have started discussing it..."

His politics are broadly of the left, but not specifically Labour. He was first politicised, he says, by the likes of Dennis Potter and John Osborne, and spent two seasons at the start of his professional career at the Liverpool Everyman Theatre with Willy Russell and Alan Bleasdale. "I went to the Everyman not knowing what right and left meant," he recalls, "and it was too late by then to ask anyone. I used to buy The Times because I liked it when it was a big broadsheet. It seemed respectable. And I remember somebody at the Everyman saying to me, 'Why are you reading that piece of shit?'. I had no idea what they were talking about. I was a latecomer."

As a struggling actor in the years that followed, Nighy also struggled with alcoholism. When he quit drink in 1992, it was with the help of his then-partner, fellow actor Diana Quick. The pair split in 2008 after 27 years and, though he doesn't talk about it in interviews, the punishing work schedule that accompanied his late-blooming celebrity was said to have been to blame. The couple's 27-year-old daughter, Mary, is now an actor, too. Does he recommend the profession to young people?

"You can ruin your life wanting to be an actor," he replies. "You see people who are university-educated, incredibly bright and intelligent, who in almost any other line of work would have lucrative, comfortable, exciting lives, with status. They could bring up a family without alarm. And yet they wanted to be an actor. I can't recommend it as a way of life, because it's full of uncertainty. There's almost 90 per cent unemployment at any given time. I think it's an honourable pursuit, and I have the utmost respect for people who are prepared to gamble their lives on it, but it can be a timebomb in your life. But then, you don't think about that when you're 20-something. People used to say all sorts of negative things to me about acting; I just thought it'd be better than working."

In spite of the hardship it has occasionally entailed, Nighy remains happy in his role. "Not long ago," he remembers, "I was sitting in the wings of a West End play, which had opened to good reviews and was considered a success. It was a matinee, and the sun was streaming through the window. I had 10 minutes between scenes and was relieved because I had already got all my laughs, so I became philosophical and I thought, 'You know what? Acting has been good to me...'." Of course, he adds, as he indulged in this reverie, he was wearing "a very nice cashmere coat – and a very good suit".

'The Best Exotic Marigold Hotel' opens on 24 February