Olivia Cooke: I'm a working class northern actress – before Hollywood, Vanity Fair would never have happened for me

And when it comes to auditions? She mimics a casting director: “‘If she sounds like that, make her Maid Number Two.’”

Happily for Cooke, the Oldham-born daughter of a police officer dad and sales rep mum, those doing the hiring for Vanity Fair saw beyond that lazy stereotype and gave her the role of the industrious, manipulative social-climbing orphan Becky Sharp in ITV’s lavish adaptation of the Thackeray classic.

• Meet the cast of Vanity Fair
• Isobel Waller-Bridge on the 'dream' of composing for Vanity Fair – and its 'weird similarities' to sister Phoebe's Fleabag
• When is Vanity Fair on TV? Everything you need to know

Unrefined candour is part of Cooke’s immense appeal. She admits, for instance, that not only had she never read the book before landing the part, she hadn’t even heard of it. And – whisper it – she’s not much of a fan of costume dramas.

“I’ve found in the past that they can be quite dreary,” she says. “They tend to marinate in their sophistication a little bit too much. Often it looks pretty but the drama is lacking. The substance isn’t actually there for me.”

With Becky Sharp, substance is not in short supply, and Cooke is sympathetic about the orphan’s selfish, scheming climb to the top of early-19th-century society. “She’s hungry for a better life, she chases status, she weaponises her sexuality, and she wants celebrity and wealth. She’s bound by society and her place as a woman.” All of which, Cooke thinks, will be very familiar to a modern audience.

When we meet on location in Surrey on a freezing day in January, the 24-year-old is sinking into a creaking prop chair in a drafty room filled with dusty picture frames and an abandoned four-poster bed. Her corset is so tight it’s restricting her ability to breathe.

She describes stumbling into acting at 14, when she started going to the Oldham Theatre Workshop. “It was just something fun to do with my friends after school,” she says.

Her best friend had an agent, so she wanted one too. After a bit of modelling and a few commercials, a casting director saw something in her – “Which was quite nice!” – and got her her first job aged 18, as Christopher Eccleston’s daughter on the BBC drama Blackout. She left sixth form early – she planned to have classical training at drama school, but didn’t get in – and “one thing led to another”.

A lead role in US horror drama Bates Motel took her to America. There, she won acclaim for her roles in films like The Quiet Ones, Me and Earl and the Dying Girl and Thoroughbreds. Earlier this year, she starred in Steven Spielberg’s sci-fi adventure Ready Player One, and will appear in the upcoming American-Spanish comedy drama Life Itself. “My trajectory has been a quick one. It has been an adrenaline rush for the past six years.”

She ponders whether her professional life would have taken off in the same way had she remained in the UK and not upped sticks to America. She concludes probably not, again citing that accent.

“I’m only guessing, and with the benefit of hindsight, but I wonder, if I’d stayed here as a working class northern actress, whether I would have had this career path. In America, my accent’s not a thing, I’m just British – ‘Where’s Manchester? In London?’ Here working-class men can rise up the ranks and do all these different accents, and I just don’t think they assume women can. But it’s definitely changing.”

Given her stateside success, you might think Cooke would be cool and maybe intimidating, but she’s lively, funny and approachable – with a line in self-deprecating humour. Describing her life in New York she says, “I love it, but when I brought my mum and sister out last year, they said, ‘Ooh, it’s just like Manchester.’ Great, I’m so glad I brought you all this way!”

This is the most comedic she’s been in a role, she says, and it’s probably her most sophisticated part, too, although she says “there are parts of Becky that are very immature, very impulsive and spontaneous. Not as measured as an adult is.”

Cooke, however, is measured – save for the moment she opens her mouth to answer a question and instead allows a burp to escape. She looks horrified but ploughs on. She says that not having to audition for the role of Becky Sharp – she was approached and then sent the script – was “bizarre”. “On set, I thought to myself, ‘I’m definitely going to get fired’, because they’ve not seen me!”

Describing herself as “pretty innocuous in real life”, she says that although it’s lovely when it happens, she rarely gets recognised. That will surely change: her face now beams down from billboards and buses to promote Vanity Fair.

She doesn’t use social media. “I don’t put myself out there much – the only time anyone sees me is when I’ve got a film out,” and keeping a normal routine is important to her. “What’s the point of being an actor and playing people from all walks of life if you can’t go down the road and get a pint of milk? Do you know what I mean?” She exaggerates her voice for dramatic effect. “Do you know what I mean?”

When asked if she seeks out strong female characters like Becky, she offers an emphatic “no”. “All women are strong if they have convictions. There are very few cases of weak female characters, just bad writing – I think it takes a bad writer to write a woman who is weak."

Though Cooke is determined rather than dastardly, Becky’s ambition is something she understands. “I love working so much, I haven’t stopped. I want to do things that challenge myself, and create things that haven’t been seen before. I strive for excellence, really.” It’s only this year she has allowed herself some time off. “I’ve always thought, ‘You might not be working next year, so get it in before someone finds out!’ Now I’ve settled into the fact that the work’s gonna come. The tap’s not gonna run dry.”

To unwind, she’ll watch Extras or The Office over and over again in bed, and says Caitlin Moran books “make you feel a lot better about your neuroses, your body, and how you feel as a woman”. She’s also thinking about the future: she’s got a producer role in upcoming projects, and would love to direct one day.

From little comments she makes, it seems there’s still perhaps a hint of imposter syndrome in Cooke – a fear that she’ll be “exposed” – that she’s still shaking off. But she never questions whether her successes, however quickly they’ve come, are deserved. “I hate saying the word ‘lucky’. It’s incredibly patronising. I’ve worked really, really hard. I’m called ‘lucky’ because of my background. Someone that’s born into it isn’t called lucky – and I think it’s the other way around. They’ve had a bit of a leg-up and their DNA is inherently really lucky. I’ve got to eat and put food on the table. I’m lucky to do something I really love, but that’s it.”

Then she takes a deep breath before closing her eyes. “I sound like a w****r.”

Vanity Fair airs on Sundays at 9pm on ITV

This article was originally published in the 15-21 September 2018 issue of Radio Times magazine