Energetic, menacing and original writer, director and actor appearing in Kvetch. Temperamental, extreme and talented madman cum tyrant and East End bovver boy made good. Clown or gangster. Attentive, courteous, private and peaceful man. Such are the Jekyll and Hyde images of Steven Berkoff. He’s wearing jeans and loose, black, zip-up sports shirt. ‘Clothes are of such a trivial nature that I’ve never considered bringing my mouth to express words to define my sartorial preferences,’ he says, writing down an idea on his notepad. ‘To give voice and value to what I wear suggests a monstrously trivial spirit.’

He obliges by admitting to a liking for high-definition tailoring, artistic workmanship, karate pants and the Parachute label. But by preference, he says, he fills his brain with the names of people who have written novels, poems and plays. That’s enough about clothes. ‘Oh f*** that,’ he replies, grinning a photocall smile. He often looks amused at himself; and sentences that might look pretentious in print are delivered with an irony and a twinkling eye.

He has chiselled features, prominent ears and nose, and eyes that stare fixedly – and sometimes madly – at a point mostly three feet from his nose, as if he’s on stage or there is no one else present. He is mesmerising, with an almost mystical quality, and his gestures float in space like a mime artist. Sitting with him is like watching a one-man show.

How does he see himself? ‘My looks are totally irrelevant to me. I just hope that I don’t look too ugly,’ he says, in gruff staccato tones that sound like a South African dalek. ‘Mainly, I like to look healthy rather than good.’ Certainly he radiates energy.

Does he think he’s ugly? ‘I don’t think so. But sometimes I look at photos of myself in the Press and think I look like some waxen head that is gradually melting. My inner spirit seems to be at defiance with my ageing. I’m in my fifties now, so I’ve scored well in terms of inner decay.’ When he found he was losing his hair 10 years ago, he’d comb it so that it wouldn’t look too threadbare. ‘But that meant I couldn’t use certain Tube stations where they had big wind tunnels.’ Then he sat in the King David Hotel in Jerusalem after directing Agamemnon in Hebrew, and shaved his head. ‘Suddenly I felt my face was revealed and I was naked again. I felt much more confident and liberated.’ His face is malleable and expressive; but he thinks it speaks of anxiety protected by aggression.

How does he see himself sexually? Sex is something about which he has written, thought and rhapsodised. ‘I don’t think about it too much. Like clothes, it’s something I don’t give words to. It doesn’t bother me one way or the other – I can be celibate for months on end, then I can be very active and lively. I’m not a slave to it and I think it highly overrated. ‘I think the promiscuous male or female is a bum. When I read about these guys in Hollywood crowing about their sex, I find it despicable.’ He talks in a poetic way, with vivid vocabulary, charge and passion. He uses his voice with a range of tones and inflections, as a marvellous instrument of expression. He is a soft man who has an intimidating image. He has great depth, and is a complex, powerful man who is strong, gentle, unconventional and fascinating. He is also candid and takes emotional risks.

‘I wouldn’t really define myself one way or the other,’ he says. ‘It’s so subjective. I think, to an extent, other people define us by their responses to us.’ OK, so he’s defined by the universe around him and his impact on that. But who is he when he’s alone in his Docklands warehouse flat? ‘I’m a private person, reflective, thoughtful, introspective, given to wild flights of imagination and daydreaming. I live very much as I did since my childhood in a world of my own where I escape through books and writing.’

He works on a book almost continuously. ‘It’s because I don’t know what else to do.

‘Of course I exist outside other people,’ he continues. ‘I suppose then I am defined in terms of the work I do. Very often I’m braver in my work than I am in life. At work I have the chance to get on stage and tell jokes in front of 500 people. At a dinner party, I probably couldn’t say a word.’ He talks seamlessly and makes eye contact briefly, from time to time. ‘I have a double side – I may be very extrovert, very free and give a lecture to hundreds of people, free associate, appear to be full of largesse, appetite, sensuality and passion. I am also a very political animal, but not doctrinally.’

Does he like himself? ‘Well,’ he coughs, ‘we all have periods of self loathing. We are divided selves. And we get schizophrenic when the two worlds drift away from each other. Yes, I love myself. I think I am wonderful, I am amazed at how wonderful I am . . .

‘And other times I am full of self loathing and think, ‘Oh my God, what have I achieved? How pathetic I am! A few scribbly words, and look at me! I’m an old man who still behaves like a teenage delinquent, and how insecure and socially inadequate I am, and what a limited range of friends and loves I have’. I sometimes feel so depressed I am ready to end it all.’ He worries that as he gets older his skills will corrode. He also has a tendency to be obsessive. ‘I get a problem that just goes round and round in my head like a record. In the Eighties I found everything bothered me: whether I was seeing people, entertaining, going out or having sex. Everything had a kind of devil attached to it.’

And he has been particularly beset by loneliness. ‘I once wrote that loneliness was like a disease. Maybe I have suffered from it to such a degree that it has created a kind of negative backwater of acid. Most of my work now is about loneliness.’ When he talks, he sounds as if he feels spiritually empty.

He is perceived as a writer who deals with the big passions, and particularly with anger. Does he think he intimidates people in life? ‘That is never deliberately done. I think people carry a response to me in their own minds before they meet me.

‘When they meet me, I am so unintimidating and gentle.’ People, he says, mistakenly confuse him with his work; his work is not a mirror image. He does, however, like his gangster image. ‘I don’t mind that either in life or film. The gangster is a rebel, risk-taker, non-compromiser and outlaw. He is an outsider.’

Some people think him rude. He gets heated and talks loudly about this. So what of his temperamental, difficult image? ‘I may have a little intolerance with people who are wilfully stupid, yuppified, Sloaney, precious and have not put their balls in an area where there is a danger of slicing them off (ie writing or on the stage). I might have shown a degree of impatience. But I can’t be rude. I feel for people. I’m a humanitarian.’ Is he a megalomaniac? ‘People think because you can do a lot of things you are a megalomaniac. I had to do all those things because I wasn’t employed. No producer ever took any of my plays. My plays were rejected, and still are.’

And is he a madman? ‘Madness is a kind of playfulness; a type of playing around with your mind and trying to be as varying as possible in whatever you do.’ He looks again into the middle distance. ‘We all have elements of madness in us.’