Susan Sarandon: She's no lazy Susan

At 61, the usually loquacious Susan Sarandon is at a loss to explain her continuing supremacy in an industry where so many other ex-models have failed: "Maybe it's because I've always been so fascinated by real people. I'm not hung up on glamour," she suggests. "Hollywood can punish actresses for getting old and fat. While I may not be fat, there's no denying my age. Other than that, I really don't know."

Perhaps it's because she's one of the few actresses of her generation whose face is still capable of physical expression? "Look, I'm not going to knock it [plastic surgery]. I think women have the right to do whatever they want to their bodies that makes them feel good. The only thing I'd say is that learning how to forgive yourself for not being perfect is probably a really positive step. I might add that motherhood doesn't exactly help your self-image when your kids are constantly telling you how bad you look. I'd like to think that it's what's inside that counts."

The eldest of nine children raised in New Jersey, she learnt early on how to grab attention, although, back in 1969, she had no acting aspirations when she accompanied her then husband Chris Sarandon to a movie casting call for the underworld drama Joe. Her husband was overlooked while Sarandon clinched a major role as a junkie teen. A quick learner, four years later she was starring opposite Jack Lemmon and Walter Matthau in The Front Page and with Robert Redford in The Great Waldo Pepper, before earning her place in Hollywood folklore with a leading role in the cult favourite The Rocky Horror Picture Show in 1975.

Her career lasted longer than her marriage, with Sarandon going on to date director Franco Amurri in the Eighties, with whom she had a daughter Eva, now 23 and also an actress. The actress met her current partner, Tim Robbins, on the set of the 1988 baseball romantic comedy Bill Durham, and has since spent the past 20 years in unmarried bliss with him and their two sons Jack, 18, and Miles, 15.

Confident in her sexuality, she claims never to have felt threatened by the fact that her partner is 12 years her junior: "Age has never been an issue but, without doubt, the hardest thing you can set yourself up for is being with somebody over a long time: having a good friend that you sleep with who will also tell you when you're full of shit and doesn't take you for granted. It's virtually impossible."

With more than 60 movies to her credit – including unforgettable performances in Thelma & Louise and The Witches of Eastwick – she finally won a best actress Academy Award for Dead Man Walking in 1995 after four previous nominations.

But her vocal support for liberal political causes has often led to ridicule: her stance against the 2003 invasion of Iraq culminated in a public outcry and death threats. "Sometimes I don't even understand the ramifications of what I say; all I know is that I just can't live with myself if I don't say something," she says. "I'm aware that I've become some kind of joke in terms of my activism but it's not something I can worry about. You have to prioritise. And it's not like my activism is something recent. I come from a generation where, growing up, if you had half a brain in your head and half a heart, you were automatically active."

Blasé about the march of time, she laughs: "I only hope 60 is the new 40, but I think people are just living better lives. My life is all about my kids. I'm not trying to cling on to my youth. It's more fun to witness their youth," says the actress, who admits that her family has less need of mothering now that her two youngest teeter on the brink of adulthood.

Take, for example, her latest role in the Wachowski brothers' action family film Speed Racer, shot in Berlin – where she hoped her sons would join her. "In the end only Miles, my younger son, came to Berlin. My older son had just graduated high school so he was touring with the guys – an international bar tour, I think! And my daughter didn't visit either because she ended up working. It's hard to let go of your kids but I'm gentle on myself as a parent and have always told myself that there's no way to do it right."

Sarandon merely sighs when you ask whether Speed Racer addressed any secret passion for race cars: "I think the fact that I drive a Prius probably says it all. When I worked with Paul Newman ten years ago [Twilight, 1998], at one point he forced me into a race car, because I was so not interested. It was fun," she says, the bored tone in her voice conveying just the opposite. "I just don't think I have that gene. I don't know whether or not it's a guy thing to watch things going round and round a track."

Based on a Sixties Japanese cartoon series, the highly stylised Speed Racer is an odd choice for an actress who usually pours such emotion into her roles: "For me, the exercise of it was to surrender to the bigger picture; to put your ego aside and try to understand how that works and serve the piece. And if you're going to try something like that, then go with the geniuses of the Wachowskis who are trying to do something different. I've been offered other movies that were big things that just seemed like a compromise, but this was a real exploration," she says.

Race cars aside, Sarandon is presently preoccupied with the US presidential race. A life-long Democrat and feminist, she has no qualms about stating her support for Barack Obama. "I've been on the road with John Edwards and now I'm supporting Obama. There's no reason why a woman shouldn't be in that office, but I'm not sure about this woman," she says in reference to Hillary Clinton: "It's insulting to assume that because you're a woman or a person of colour, you would automatically back any woman or a person of colour. It's a little more complicated than that."

'Speed Racer' is out now

Interesting? Click here to explore further