Stand by for action! In the new big-screen take on Thunderbirds, Sophia Myles is even more eye-catching than the International Rescue supermachines

“You’re a Thunderbird, aren’t you?” Sophia Myles lets the accusations fly, and to be honest, it’s a fair cop – in his youth, Hotdog did indeed watch Thunderbirds. Occasionally. If there was nothing else on. Which comes as a bit of a surprise to the similarly aged Miss Myles, until now under the impression that the series wasn’t on the box when she was a kid. “Oh shit, was it on? I’ve been doing so many interviews saying it wasn’t on.” Yeah, after Neighbours, in that 6pm BBC2 geek slot. “Really? So all the ardent fans are going to say, ‘She’s lying, it was on.'”

Since landing the role of International Rescue’s London agent Lady Penelope Creighton-Ward at the close of 2002, however, the 24-year old actress has had plenty of time to become accustomed with the inner workings of a British institution. And though she’s stepping into the miniature shoes of an ever-so-slightly misproportioned marionette, Myles is under no illusions about the magnitude of taking on a national icon. “It was very much a thing of [excited] ‘Oh my God, I’m going to play Lady Penelope,'” she recalls. “And then, [more panicked] ‘Oh my God, I’ve got to play Lady Penelope!’ Two days after Working Title cast me they told the press, and Ron [Cook, who plays trusty chauffeur Parker] and myself were on, like, page four in loads of newspapers.’

Just over 18 months later we’re sitting in the regal surroundings of Cliveden House, the Berkshire stately home that doubles for Lady Penelope’s country pad in the movie. Indeed, with iconic pink limo FAB 1 (now a Ford Thunderbird in place of the original Rolls Royce) sitting out in the driveway, you’d almost believe you’d popped round to Lady P’s for afternoon tea were it not for the fact that Myles’ casual t-shirt and jeans ensemble – pink Thunderbirds top excepted – might not find its way into the aristocrat’s ever-changing rose-tinted wardrobe.

“It’s lovely because she’s such a positive role model for children,” says Myles of her impeccably dressed screen alter ego. “She’s very intelligent, she’s good looking, she’s feisty, but without being provocative. It’s going back to the sort of timeless glamour as opposed to get the midriff out and shaking your arse, which you don’t need to do.”

But despite the lack of Buffy-style micro skirts, Lady Penelope was obviously educated at the same kick-male-butt school as Sarah Michelle Gellar and Alias‘ Jennifer Garner, albeit with a few more comedy sound effects thrown in. “It’s hard work every day doing physical stuff – I’ve never been to a gym really, and its tough on you – but [the fighting] actually turned out to be one of my favourite scenes,” Myles explains. “I could do it all but not very well. Any time that I didn’t look elegant or cool enough, they would put either of my two amazing stunt doubles in.”

Myles could probably do worse than speak to Thunderbirds director Jonathan Frakes – himself a veteran of seven seasons of Star Trek: The Next Generation – about the attention she can doubtless expect in the wake of the film’s release. Nonetheless, she’s somewhat pragmatic about the fact that change-fearing fanboys might be less than enamoured with the (often necessary) alterations meted out to Gerry Anderson’s puppet universe. “If they don’t like it, they don’t like it,” she declares matter-of-factly. “I’m not worried because now I’m being sent letters from four-year-old children who’ve drawn me pictures of Thunderbird 1 and Lady Penelope’s car, and you see little kids just sitting in a cinema, silent, for 90 minutes. We wanted to make a film that allowed children to have their imaginations back, something very pure, and that’s what we’ve done.”

With the geek heaven of vampires vs werewolves actioner Underworld behind her (she played scheming bloodsucker Erika), Myles has at least had some time to get used to the intense aficionado attention that goes hand in hand with the scifi/fantasy genre – for starters, at least two fansites have been created in her name. “I don’t look at them very often because there’s, like, message boards and things on there,” she says. “Up to now its been okay but I always worry that someone… you know its better not to read those things. And the IMDB message boards are always terrifying if you actually look at what they’re talking about, the things they have to say.”

That said, it looks like she won’t be getting much time to surf the net, with the Kevin Reynolds-directed Tristan And Isolde in the can, and production just about to start on Terry Ghost World Zwigoff’s latest. “It’s really cool, it’s called Art School Confidential, and I’ll be playing an American,” she explains with the sort of excitement reserved for people who really can’t wait to get cracking. “It’s set in New York and it’s based on a comic strip. It’s written by Dan Clowes, who did Ghost World, and it’s about American kids going to art school in their late teens and early twenties. It’s myself, John Malkovich, Angelica Huston, Jim Broadbent, Steve Buscemi and Anthony Minghella’s son Max. It’s a dark comedy and funny as hell.”

So with her movie career threatening to explode into life (box office depending, another Thunderbirds outing could be on the cards), it comes as quite a surprise that Myles describes her recent purchase of a London flat as “the biggest achievement of my life.” Indeed, Myles’ decision to turn down the offer of a place at Cambridge University now seems like one of the best moves she’ll ever make. “[I have] no regrets, because I completely fell in love with this industry as soon as I walked on to my first job,” she points out. “And I was thinking, well, I can either go and sit in a classroom and study Jane Austen or Harold Pinter plays, or I can make Mansfield Park and work with Harold Pinter, and be paid to do it, and be in the cinema. So no regrets.” Or as Lady Penelope might say, FAB.

Thunderbirds is in cinemas from 23 July