He is 31, a Londoner who moved to Los Angeles 18 months ago: one more name to add to the roll-call of bright young actors who have slung their hook and headed for Hollywood, fed up with the limitations of Blighty and its moribund film industry. The work didn't dry up for Roth, as it had for many others, but it did grind him down. 'I was doing jobs that I didn't really care about, all over Europe,' he recalls, 'like To Kill a Priest, which was atrocious - I'd certainly work with Agnieszka (Holland, the director) again, but it was her bad movie, you know? Then I did this awful film in Ethiopia, and another terrible film in Australia called . . . God what was it called? Backsliding, that was it.' Didn't see it, I'm afraid. 'Neither did I. I don't ever want to see it. Completely miscast.'
Yet it all looked so promising at the start. Abandoning art school for fringe theatre, Roth practically shattered the screen in his 1983 debut, playing a skinhead in the late Alan Clarke's explosive study of violence, Made in Britain. Clarke was evidently something of a guru to the young actor. 'Alan Clarke was the man. He was the director who made the real films about our country, consistently brave things like Elephant and Scum. Made in Britain was my first time in front of a camera, and Chris Menges was cameraman. He taught me how to act. I thought all films were going to be like that - I had no reason to suspect that they'd be any different.' Before he learned just how different things could be, Roth worked with an impressive line- up of talents - Menges again in A World Apart, Peter Greenaway in The Cook, the Thief, His Wife and Her Lover, Robert Altman in Vincent and Theo. My own favourite, though, was his role as John Hurt's idiot side-kick in Stephen Frears's superb thriller, The Hit (1984). Roth's performance was a study in twitchy, instinctive aggression, and his broken-glass south London accent shredded whatever nerves the viewer had left.
The Evening Standard acknowledged that performance with its Most Promising Newcomer award. Roth is blithely dismissive of it now. 'John Hurt said to me: 'They've been calling me a newcomer for 10 years, doesn't mean shit', and he was absolutely right.' Perhaps realising the limits of playing yobs and berks, Roth decided to up sticks and go west: from Wallyhood to Hollywood. Last year he made his American debut in a low-budget independent film, Jumpin' at the Boneyard, as an Irish-American who's trying to save his crack-head brother in the Bronx. But it's Reservoir Dogs, one of the first films of 1993,that should put Roth ahead of the pack. Quentin Tarantino's astonishing debut is a blood- bolted cops-and-robbers movie about a diamond heist that goes wrong. Constructed in a complex shuffle of prologue and aftermath, Reservoir Dogs piles up bodies higher than a Jacobean revenge drama, and manages to be funny at the same time. Roth himself plays a gang member, Mr Orange. The film lasts as long as it takes him to bleed to death. It's decidedly not for the faint-hearted.
Roth contends that Dogs is 'one of those films which could be shot anywhere in the world', though I'm not sure that a British director could catch the rhythm and texture of a closed masculine world the way Tarantino has done. Roth disagrees. 'Ken Loach, Mike Leigh, Stephen Frears . . . and probably countless others who can't find the money. What we're doing instead is Merchant Ivory, the Jeremy Irons-Kenneth Branagh thing, which is basically made to sell to America. The French make films for the French, but we make them to export.'
While the domestic market goes slowly down the tubes, Roth is on the up, and knows it. 'The truth is, the more successful somebody like Gary Oldman is, the more jobs I get. There's going to come a time when they can't get Gary, they can't get Danny (Day-Lewis), so they'll think 'let's get Roth in, he's cheap'.'
A glance around the hushed Savoy suite gives warning: he's not going to be cheap for much longer.
'Reservoir Dogs' opens on 8 Jan at MGMs Haymarket, Tott Ct Rd & Chelsea; Camden Plaza, Ritzy Brixton, Screen on the Green, and across the country.