Three years ago, Tom Sizemore was in bad shape. Very bad shape. He’d landed a once-in-a-lifetime part - the chance to work with both Al Pacino and Robert De Niro in Michael Mann’s Heat - but even that wasn’t enough to distract him from his main preoccupation: heroin. Partying with Hollywood friends and caught up in what he now describes as a “rollercoastering kind of substance abuse”, Sizemore paid little attention to the work he was doing. In fact it looked as though his sliding career path would rival Mickey Rourke’s - only without the middle fame stage. But De Niro, a survivor of Hollywood’s great ‘70s excess, saw all the signs. After the last day of shooting, De Niro bundled Sizemore into a car to the airport, dragged him onto a plane and booked him into rehab. Talking him through the tough early days of trying to stay clean, De Niro had a mantra: “You gotta stay strong you gotta stay strong.....”

Tom Sizemore, 34, has been clean and sober ever since, and he’s seen the same cycle of dependency played out by many of his closest friends. Some, like Robert Downey Jr, have been lucky so far. “Robert was always a very dear friend of mine,” Sizemore reflects, “and it’s been a tragedy watching that. But he’s got it together right now, so I hope and pray he makes it.” Others, like Chris Farley, were not so lucky. “Chris was also a good friend of mine,” says Sizemore. “His death was a horrible tragedy. I still have a hard time thinking about that. But it’s always their choice. It’s sad, it’s just sad.” he pauses for a moment, visibly moved. “Let’s leave it at that.”

The new Tom Sizemore is a thoroughly reformed man. He’s as impressive as ever in the lavishly praised Saving Private Ryan. And in Scotland today, having finished shooting his part in The Match, one of the many movies he’s been in recently, he’s full of the joys of everyday life. And he’s especially ebullient about his wife, Maeve Quinlan, star of US soap The Bold and the Beautiful. “We just bought a house in Benedict Canyon,” Sizemore beams, willing and eager to talk about his personal situation. “We’re very happy, it’s very domestic and we’re a monogamous married couple. I just spent six weeks without her, which is the longest time we’ve spent apart. but we’ve made a pact now, because this was too long. We’ve decided to go no longer than a two-week separation.”

For Sizemore, domestic bliss is something of a novelty. Raised in Detroit, Michigan - the lapsed industrial “motor city” - his family struggled to get by. Their fortunes were changed somewhat when his father - a teacher - won a scholarship to Harvard to study philosophy, but the rest of his family didn’t automatically reap the benefits. Sizemore has since claimed that two of his brothers sold smack and that his mother’s brother was “a pimp”.

Ironically, it was seeing De Niro in Taxi Driver at the age of 13 that shaped Sizemore’s future. He was taken to the movie by his father and his uncle, and halfway through he heard his father mutter, “We shouldn’t have brought Thomas to this movie.” But Thomas didn’t mind. The film, he said, “blew me away”. He’s seen Taxi Driver a further 26 times. “Working on movies can be tiring,” he says, “but I watch something like that and it gets me all excited again.”

As a teenager, Sizemore sang tenor in musicals staged by local theatre groups. Joseph and His Amazing Technicolor Dreamcoat, The Music Man and HMS Pinafore...he even played the lead in Bye Bye Birdie. Which might explain why he was so peeved not to have been approached by Alan Parker for his film treatment of Tim Rice and Andrew Lloyd Webber’s Evita. “I could have sung Che,” he states, deadly serious. “I wasn’t even considered, I’m sure, but I would have loved to have played that part. I’m actually going to start taking singing lessons again just for myself, just for fun, but who knows where it could lead? Unfortunately, I smoke, which I’m hoping to give up. It’ll be the last bad habit I give up - after that I won’t have any more. When I stop smoking, I’ll be perfect!”

Sizemore may have had the last laugh, though, thanks to last year’s monster-running-amok-in-a-museum B-movie The Relic. It’s the one film he’s ever made in which he was the undisputed, top-of-the-bill star. It could even - at a stretch - be viewed as the film that finally proved that Sizemore could actually cut it as a leading man. But let’s be honest, it wasn’t....very good. “Even though it did well at the box office and I think my performance is fine, I thought it could have been a better movie,” Sizemore says. “But it was nice to be the star of a hit movie and I proved I could in fact carry a picture. It opened at number one in America. I beat Evita! That was quite an accomplishment - I’ve got more fans than people think.”

Having left school, Sizemore studied theatre at Temple University in Pennsylvania and graduated with a Master’s Degree in 1986. Then, after dabbling in television, he served an apprenticeship on films as diverse as Born on the Fourth of July (1989), Blue Steel (1990) and Point Break (1991), eventually graduating to prominent roles in True Romance (1993) and Wyatt Earp (1994). But it was Sizemore’s performance as manic cop Jack Scagnetti in Oliver Stone’s scattershot satire Natural Born Killers (1994) that promised to be the breakthrough. Sadly, while his career was taking off, his heroin use was dragging him down.

On the big screen, Sizemore’s looks testify to his hedonistic past, giving him a lived-in, slightly dishevelled look - the kind that draws comparisons with Robert Mitchum. In the flesh, though, he looks healthy, sporting a tan that even a steady six weeks of Glasgow rain hasn’t diminished. Bizarrely, given Sizemore’s roles to date, The Match is a comedy in which the fate of a Scottish village’s only pub rests on the outcome of an amateur football match. It’s the sort of film where you’d expect to see the likes of Richard E Grant, Max Beesley, Neil Morrissey, even Alan Shearer - not the sort of film you’d expect to see Tom Sizemore in. Or that even Tom Sizemore would expect to see Tom Sizemore in. “I wasn’t sure what I wanted to do after Saving Private Ryan,” he explains, “but then the script came along and it was a totally different part from usual. My character’s an American, an ex-air force guy who was a fighter pilot and has now become the local drunk in this little Scottish town where he was based during Desert Storm. It’s a nice little romantic comedy and I really liked the people involved. The script is really lovely, really sweet.”

The Match could not be further removed from Saving Private Ryan. Sizemore is proud of his work on Spielberg’s visually harrowing, emotionally gruelling war drama and he feels he worked to his full capabilities while making the film. “I was very strong,” he says. “It was the first time I worked every day on a movie, so I got to feel the pressures and responsibilities of carrying a movie of this magnitude.” And after his wilderness years, “carrying” a movie is something Sizemore is starting to care more about. Although he has always managed to shine in ensemble pieces such as Heat and Saving Private Ryan, it’s clearly important for him to break free of the pack.

“I like it that Steven Spielberg says I’m a leading man”, he says. “I want to play leading-man roles. I mean, if you look at leading men, there are all kinds of different ones. You don’t necessarily have to be a knockdown beauty-boy to be a leading man. I don’t think Tom Hanks would disagree with me when I say that he doesn’t look like a model. He looks like a person. I would say Brad Pitt is better looking than myself, but there’s room for every type of person. I think being a movie star is about whether an audience can watch you and care about you. Do you have the charm and the......er, I’m missing the word....grace?” He frowns. “No, that’s not it....watchability! No.....” Finally he gives up altogether. “The kind of charm, grace and watchability that means people will feel comfortable letting you into their lives and watching you for two and a half hours. There’s a word which means a combination of what I’m saying - charm, watchability, easiness. Er, basically there are lots of ways of being attractive.....Hopefully I’ll think of this word. I wish I could think of it. It’s driving me nuts!”

In his nine-year movie career, Sizemore has managed to work with some of America’s finest directors - Oliver Stone (Born on the Fourth of July, Natural Born Killers), Michael Mann (Heat), Steven Spielberg - and he’s about to add another, Martin Scorsese, when he stars opposite Nicolas Cage in Bringing Out the Dead. Cage plays a washed-out paramedic working in New York’s notorious Hell’s Kitchen district who is haunted by the ghosts of patients he failed to save. Sizemore will play his former working partner, and he can’t wait to get started. “I hear Scorsese and Spielberg are similar,” he says, suddenly fired up, “in that they want to tell the truth about their subject and are very passionate about their vision. I also hear that watching Scorsese direct is very enjoyable. I’m really anxious to start that picture.”

Before then he’ll be seen in On Any Given Sunday, the film that marks his third collaboration with Oliver Stone. “It’s a really brutal look at American football and the National Football League,” Sizemore says. “I play this superstar player whose vertebrae are all screwed up and he’s one shot away from being a quadraplegic, or possibly even dying. He’s an all-American hero and doesn’t want anyone to know because he wants to keep playing. It’s about all the shit that goes on in the NFL. I start that movie while I’m doing Scorsese’s. I knew this might happen, but I’m glad it’s worked out so I can do both. I wanted to do the Scorsese movie desperately.”

Tom Sizemore is facing a pretty enviable career junction. But which way will he travel? Would he prefer to pursue the bigger names, even if it meant smaller roles, or take a bigger role in a lesser director’s film? “I’d probably take the smaller role with the better director,” Sizemore says after a long pause. “That’s been my philosophy so far. Now though, I’m being offered leads in pictures, both good and bad. I’ve got to be careful about what I do because I really care about what type of movie I make. I think movies are important and I try to do quality material. There’s been an upsurge in my career after this performance in Ryan, which is very flattering and great, but it’s hard to keep that standard up. I’m not going to do a Saving Private Ryan again, probably. Maybe with Bringing Out the Dead, Martin Scorsese’s going to make another GoodFellas. He can, of course, and it would be wonderful to be in another classic. Because I think Ryan’s a classic.”

He hesitates. “Actually, I think Heat’s a classic. I think I might have been in - potentially - maybe three classics. That sounds kinda like I’m bragging, but Natural Born Killers has become an underground classic. And Heat is such an underrated movie. It’s the best cops-and-robbers movie in a long time. Michael Mann is undervalued: he’s a great director who tackles serious subjects. I’m hoping to do another movie with him soon, a big drugs movie about the Golden Triangle and drugs gangs. Sorry, Michael, if I’m revealing this. I don’t think he’ll mind. He’s definitely going to do it; he’s doing three movies back to back.”

So will Sizemore ever make the quantum leap to the ultimate and most lucrative level of stardom: the romantic male lead? “Well, I kind of have a really nice relationship with Tom Hanks in Saving Private Ryan,” he laughs. “It’s just that he’s not a woman.” But he does give the matter some thought. “When am I going to get the romantic lead? I’m working on that and I don’t think it will be too long. A couple of the movies I’m looking at starring in - that’s one of the main reasons I’m looking at them. It doesn’t happen in Marty’s film and it doesn’t happen in Stone’s movie, but hopefully it will be something after that.”

The Florentine, perhaps, in which he appears with his real-life wife? “Oh yeah, I’m romantic in that,” he explodes. “How could I forget about that? Especially as I helped put the film together! There’s a great cast: Chris Penn, Michael Madsen, Mary Stuart Masterson.....I play someone who comes back to town and my ex-girlfriend is getting married. But I kind of get a romantic notion towards this cafe waitress, who my wife Maeve plays. She’s really terrific in it. We’re going to tour it around the festivals when it comes out next year.”

Nowadays Sizemore seems to have swapped his reliance on substances with a thirst for work. Having recently played gangster John Gotti in the TV mini-series Witness to the Mob, and with an intense shooting schedule lined up, he’s also writing a screenplay “about a love affair, based on my early days when I lived in New York and was poor”. Then next year there’s the possibility of shooting Out On My Feet, with De Niro and Mark Wahlberg. “My life is completely turned around,” says Sizemore proudly. “I’m a success story. I’m one of the winners - knock on wood. You have to take it a day at a time, but my old life seems a long, long way away. Y’know? It seems like I’m a different Tom now.”