Tuppence Middleton: "You always fear you're going to get found out..."

“Apologies if anyone gets sick of me in January,” says Tuppence Middleton, laughing. With her role as Helene Kuragin in War and Peace coming hot on the heels of the first few episodes of Dickensian, in which she plays Miss Havisham, Middleton will be all over our screens in early 2016. But before talk turns to her star turns, the 28-year-old wants to say hello to her regular Big Issue vendor.

“John Gregg in Muswell Hill is such a lovely man,” she says. “Every week he tells me what is in the issue, so this week is going to be funny. He mentioned me when he did his My Pitch interview, so I want to return the favour. Please save me a copy, John!”

Shout out complete, we turn to those two big roles…

“I loved having an excuse to read all of War and Peace by a deadline,” she says. “I started it three years ago, got a third of the way through, and then life and work got in the way.

It has these huge themes, but so much of it is about youth and being in love

“So this time last year I booked myself into a hotel in Brussels over New Year and sat for four days making sure I finished it. It was such a pleasure.”

In an eye-catching role, Middleton plays hedonistic Helene, whose hinted at incestuous relationship with her brother is expanded by screenwriter Andrew Davies. Wild parties and scheming are the order of the day.

“She knows how to get what she wants – socially, financially, romantically. Helene is a master manipulator,” she says. “Andrew Davies is brilliant at finding the essence of the story. It has these huge themes, but so much of it is about youth and being in love. I wanted Helene to be fun as well as this villainous seductress. I want her to be liberated and likeable, even though we know she is no good.”

Middleton’s success has come gradually. A string of independent film roles preceded her casting (as a psychic Icelandic DJ) in Netflix’s cult hit sci-fi series, Sense8. It is, she says, part of the plan, citing regular Coen Brothers collaborator Frances McDormand and Anne Marie Duff as role models.

“I always wanted this to be a career long term,” she says. “I didn’t want to be in a film and straight away be famous. Where do you go from there when you are 21 with all this success?

“A lot of people are equipped for that, but I wasn’t ready at 21. I needed to get to know myself, get to know my tastes, and figure out what I want to do with my career.”

I couldn’t have more respect for him and he always has time to give advice

The role of Miss Havisham is one Middleton had marked as a future career ambition. Instead, she is following in the footsteps of Helena Bonham Carter, Gillian Anderson, Charlotte Rampling – “I can’t think about it too much otherwise I start to panic” – but playing one of Dickens’ best creations as a young woman.

“People know the character so well that she comes with a fully formed image,” she says. “Miss Havisham is this manipulative older woman who has lost her mind after this tragic jilting. But in Dickensian she is a young woman with the same dreams and ambitions as anyone else.

“And in our version she is so forward thinking. It is a shame it is destined to go wrong for her, because she shows so much potential. Despite knowing her fate, I think the audience still invests in that love story.”

Middleton went straight from filming War and Peace in snowy Lithuania to the impressive Dickensian studio set in Greenford, West London. One constant through the transition was Stephen Rea, who plays her father in the former and Inspector Bucket in the latter.

“He really looked after me on both shoots. I couldn’t have more respect for him and he always has time to give advice,” she says.

“It was so nice to hear all of those people you grew up watching on TV and film talking about their lives. You get so many different generations, but actors are always young at heart. I hope to still be doing this into my 80s or 90s. So I need to make my choices carefully.”

Despite a second series of Sense8 that will take up most of 2016 already lined up, plus a possible second outing for Dickensian, Middleton admits to nerves as she looks ahead.

“Both War and Peace and Dickensian should travel well to America, which is great,” she says. “I would just love to keep working.

“You never get rid of that feeling that this could be your last job and you will never work again. I think you always fear you are going to get found out…”

War and Peace is on Sundays at 9pm on BBC One