Meet Bel Powley – the new IT Girl of British cinema

Still only 23, the London-born star of The Diary of a Teenage Girl could only laugh in response to the gushing praise she received from a host of American interviewers.

“I’m a Sundance virgin!” she squealed to the delight of her hosts at the A-list US film festival. “It’s been amazing. The premiere was yesterday. I was watching it so intensely and then the credits started and I broke down. I think I was just overwhelmed with happiness. It’s been going so well.”

Indeed it should be. Not since Keira Knightley brought a breath of fresh air to British cinema 13 long years ago has an actress been so embraced.

And in such an in-your-face role. For Minnie in The Diary of a Teenage Girl evolves from wide-eyed teen fantasist to a young lady with a fierce sexual appetite that is sated by an affair with her mother’s boyfriend. Powley’s appeal in the film comes courtesy of some immersive acting – she’s quite clearly a Brit yet the film is set in San Francisco in the 1970s; it’s an American story.

Moreover she brings depth and plausibility to a role that involved some tricky moments, not least the off-limits nature of teen sexuality that underpins the story.

“The movie is about a girl who loses her virginity to her mum’s boyfriend,” says Powley with refreshing openness. “It doesn’t happen all the time but I think that female sexuality in teenagers isn’t a subject that is addressed a lot, if at all. There are a lot of movies about teenage boys wanting to get laid and losing their virginity and discovering themselves and if you think about it there aren’t any about women.

“It’s kind of a taboo subject. Young female characters can be very 2-D characters: she’s a virginal princess waiting for her prince charming or if you have a lot of sex you’re a slut.”

Whilst Powley’s father – Mark Powley – is an actor she herself received no formal training. In fact her professional CV is pretty meagre. She was one of the leads in the TV series M.I. High from 2007 to 2008 and in 2013 joined the ensemble cast of TV’s Benidorm.

But theatre was her training ground. As a teenager she appeared at the Royal Court in Tusk Tusk. (The Guardian’s critic Michael Billington called her “astonishing”.) Two years later she was on Broadway. For Powley, that’s where it all happened.

“Standing on the stage in front of a thousand people in the West End or on Broadway is a really intense thing. I learned the whole script before I got (to America) so that when I got there I had it all down: all 90 pages. I could recite it. It was really useful because (it meant) we could dip in and out of scenes, we could change the schedule because I always knew where I was coming from.”

It appears almost prurient to discuss the film’s numerous sex scenes but Powley’s prepared for it. Was she nervous? The question almost needn’t be asked…

“Yeah. It’s definitely scary exposing yourself in that way physically and mentally. But when I read the script I was so taken aback at the honesty in the portrayal of the teenage girl.

“I think that’s what attracted me so much to the script: it captured so well the feeling of being a teenage girl when you’re so hormonal and everything’s so visceral and frustrating and the extremity of emotion.”