ROBERT Carlyle has developed a taste for gore.

After being the sole survivor of a group of snowbound settlers forced to eat one another to keep alive in Antonia Bird's period horror flick Ravenous, he's tucking in to more mouthfuls of raw flesh in 28 Weeks Later, a scary sequel to Danny Boyle's 2002 apocalyptic thriller about zombies roaming London.

"It's not a particular genre you go to, it's more the quality of the story, " he says. So blood isn't the attraction? "Maybe it is for you.

But I'm an actor. If I was 19 you could ask me that question. But I've made about 33 movies. A lot of them have been bloody. So I'm well past that." To suggestions that it can't require a lot of talent to play a heavily made-up zombie, he retorts, "F*** off, I'd say to that . . .

next question please."

It's the morning after the West End premiere of 28 Weeks Later.

Having weathered a barrage of sometimes prurient questions, the 42-year-old Glaswegian actor, best known as the psychotic thug Begbie in Boyle's Trainspotting, has found sanctuary in the Soho Hotel.

"The first thing about 28 Weeks is that it's an entertainment, " he tells me, lighting a cigarette. "It's to be enjoyed, a Saturday night movie.

But if you accept the premise of a rage virus that rapidly turns the whole population into vengeful zombies, there are obvious contemporary resonances. With all the masses of rage throughout the world and people blowing themselves up in buses and trains and planes and killing children, a logical conclusion for the human species is to end up wiping each other out, killing our neighbours and ourselves."

28 Weeks Later, playing on fears triggered by Aids and more recently by SARS and bird flu, serves its human meat spiced with disturbing metaphors for a post9/11 world. The US declares that the war against the rage virus that annihilated mainland Britain in 28 Days Later has been won. American troops have established a safe haven on the Isle of Dogs in London Docklands . . . sealed off from the rest of the city with massive security checks - to which the first wave of refugees return. It doesn't require much imagination to see this as a version of the Green Zone in Baghdad, or the menacing zombies outside as al-Qaida terrorists.

"There are political elements with a small 'p' within the movie, " says Carlyle. "They speak loudly to me. But you could miss them if you don't want to see them.

It's not in your face. It's something only to suggest, otherwise it becomes a different film. You give a nod to it and no more. Of course 28 Weeks belongs in the horror genre, and you have to be true to that, but it's driven by the characters and the way they behave. You kind of invest in them, and suddenly they're you."

Carlyle plays a survivor who . . . as we see in a nightmare flashback . . .

escaped the original catastrophic outbreak, but only by leaving his wife behind to die. Now he's reunited on the Isle of Dogs with his teenage daughter and son, haunted by his guilt. "Everything that happens turns on this, " says Carlyle. "You could argue that what he did was right. You could argue that it was wrong. He does what he has to do. All the characters are faced with momentous split-second moral decisions . . . the American commander, the army doctor, even the children. That's what I'm always looking for in a script. It's what makes good drama."

If 28 Weeks Later is a rare example of a sequel that's even better than the original, put it down to Danny Boyle's inspired choice of Juan Carlos Fresnadillo . . . a Spaniard who knew nothing about London . . . to take over from him as director. "Danny wanted someone fresh who could bring something different to the story, an outsider, " says Carlyle.

Fresnadillo was drawn to the idea of characters who are all victims of fate having dealt in his brilliant 2003 metaphysical thriller Intacto with characters who cheat fate, and then don't know what to do with their undeserved good luck. If he's obsessed by the vagaries of chance, it's hardly surprising.

When he was nine he was witness to an appalling human catastrophe. "As my mother was driving us past the airport at Santa Cruz de Tenerife, I remember seeing a huge jumbo jet on the runway waiting to take off.

When we reached a cafe, ambulances passed us travelling in the opposite direction. I saw a cloud of dark smoke illuminated by the airport lights. There was a sour smell in the air. Another jumbo coming in to land had hit the jumbo on the runway . . . 578 people lost their lives."

He sought to echo the shock to this reality in 28 Weeks Later. "I'm not a big fan of horror films, " he says. "I never thought to make a violent film like this. But in terms of being absolutely honest with the concept of the film, it seemed to me the best way was to bring reality to this world, to try to make a kind of documentary about what was happening, otherwise it would be fake. I wanted to give the audience something they can believe because it's something you can feel so close to you."

He achieves this not just by using hand-held cameras throughout, capturing the hysteria of marauding zombies erupting on to the streets while the American military unleash murderous fire on Canary Wharf, but by keeping the focus always on the human side of the apocalyptic vision. "I don't believe in black-and-white, " he says. "I don't believe in bad guys and good guys. Everyone here is a victim of something bigger than themselves. The story is a mirror of reality now . . . of our time and of our world. Obviously you're dealing with a genre, but all of the events in the movie are built around something real and possible, something you can check in the newspaper. I love when you're working with monsters, but these monsters have a human side."

Carlyle doesn't believe in black and white either. Apart from The Full Monty . . . and perhaps the Ken Loach movies Riff Raff and Carla's Song . . . Carlyle invariably plays flawed heroes or villains who evoke some sympathy, the feckless father in Angela's Ashes, the gay lover in Priest, the baddie Renard with a bullet in his skull that is slowly killing him in The World Is Not Enough. He's currently filming The Last Enemy in Romania. "It's about surveillance and spying, not on a grand scale but on a more mundane daily level, " he says. "It's set in 2013, but all the stuff that's there is there now. It's very frightening."

He lives in London with his wife and three children, not far from where 28 Weeks Later was filmed. "If you go back to the beginning when I thought of being an actor back in Glasgow, I can't believe I'm sitting here. It's far beyond what I ever expected. I'm an easily contented person. I never strived to be anything other than what I am. I enjoy what I do.

I've no intention of moving to America. I never have. I could have done loads of stuff there had I been inclined. But what I do is from a British sensibility. It's from a particular class as well, and a particular social structure. Therefore I should be here in this country to observe that.

"There's no point in me looking out the window in Los Angeles.

There's no life there that relates to me. My love has always been of British cinema of the late 1950s and early 1960s, films like Saturday Night And Sunday Morning and The Loneliness Of The Long Distance Runner. These things are documents of the time. If I ever do anything, that's what I want to do. I want to be involved in films that are documents of the time."

'28 Weeks Later' opened nationwide on Friday