Rebecca Ferguson is a strong believer in confronting your fears. Going into Mission: Impossible - Rogue Nation she told herself that she would seize the day and face every challenge, no matter how daunting, as it came along.

Director Christopher McQuarrie's eagerly anticipated film would require Ms Ferguson to tackle many of her own stunts in the spectacular action sequences that the hugely successful franchise is famous for.

She knew too, of course, that her co-star, Tom Cruise, who returns as IMF [Impossible Missions Force] operative Ethan Hunt, is an actor who relishes and thrives on doing his own hair-raising stunt work and that spurred her on to do as much of her own action as possible - even if it meant facing her dread of heights.

"I suffered from vertigo before making this film. I wouldn't go in an elevator before - I wouldn't have jumped from two metres but I overcame that fear of heights and it's because you are part of a team and you know what's needed, and also I knew that if I couldn't do it there was always Lucy Cork my stunt double who would jump in.

"But Tom does all of his stunts, so I sort of said to myself, 'come on, you only live once, and this is happening right now... And I trusted the equipment and I trusted the people, I double checked security, I've seen how Tom is working and I just had to go for it. And I did. But for me to watch footage from the film is something else because it takes me back to when we did all these incredible things and I think 'wow, I did that!' It may be a two minute action sequence but it took me months of training to get to that point."

Indeed it did. Once Ms Ferguson knew that she had landed the part of the mysterious undercover agent Ilsa Faust she embarked on a gruelling fitness and diet regime to prepare for Mission: Impossible - Rogue Nation.

"We had a month and a half to prepare before filming started and it was six hours a day, six days a week, which was incredibly intense but also organised and scheduled and within that schedule it would be diverse, too.

"So I would have Pilates, I would have martial arts training, I would do general fitness. It was tough but essential because you have to prepare and you have to be in the best possible condition to survive on a film like this."

She was filming The Red Tent when she first sent in an audition tape to Rogue Nation director Christopher McQuarrie. Next up, during a 24-hour break from filming the biblical TV drama, she headed to London for a meeting with McQuarrie and star Tom Cruise who instantly made her feel at ease.

"It was actually the most relaxing meeting I have ever had. Because I was working, I was in the mind-set of filming and working and from one day to the next and then, I had just 24 hours in London to do the meeting with Tom.

"I arrived at this beautiful house and Tom Cruise was there with [director] Chris McQuarrie and I didn't really have time to feel nervous because I knew I had to go back on set for The Red Tent so it was straight in. And the first thing that happened was that we just ordered coffee and we sat down and talked. And we talked about life and work and the characters, and two or three hours flew by. It was just so easy.

"The whole energy in the room was a group of people wanting to get the best out of someone and helping me achieve that. There's the whole idea of 'Tom Cruise' but I think that's what the media creates, they create a buzz around people and I live in a fishing village in Sweden and I love it there, it's small and calm, and I don't judge people.

"I love meeting people and so even if people have their opinions about someone - no matter who it is - I try to be neutral. So when I went into that room the only nerves I had were not about meeting Tom but the fact that I knew I would love to do the role and be a part of the film.

"It was 'I hope we work well together and I hope he likes me and I like him..' And I did like him, very much, because he was just Tom and there was no shield, he was just who he is. And he was there with me, as was Chris, and the producers and the cinematographer, so it was like being brought into a team that know each other very well.

Her character, Ilsa Faust, is right at the heart of the story but the audience will have to work out exactly whose side she is on. Ethan Hunt and his IMF [Impossible Missions Force] team are tracking a mysterious organisation known as The Syndicate although it quickly becomes apparent that The Syndicate are also stalking and seeking to kill the IMF operatives.

"No we don't know her agenda and she is very mysterious. What we do know is that she is highly intelligent and equally as trained as Ethan, which is interesting and fascinating because the audience never knows when the turn will come and where the story will go.

"And when somebody works undercover it's like the famous Stockholm Syndrome, and we never quite know her reasons and her purpose. So her story and her history are as interesting as to her choices and where she is actually going. But she is brought in to help eradicate the so called Syndicate team which wants to take down the IMF team. So we start out thinking Ilsa is one thing and then we start to wonder if she is something else.

Ms Ferguson has long been a fan of action films and in particular, the Mission: Impossible franchise. "I love action movies and I love Mission: Impossible films. I absolutely love them. I love action films when they are intelligent and I love well-choreographed fight scenes. I used to watch a lot of Jet Li films. I love movement and dance and a beautifully choreographed fight scene is all movement and rhythm."

She is a keen amateur dancer and once worked in a studio in Sweden, which taught the Argentinian tango. "And one of the things I learnt there was control of the body and that fit in beautifully with this dynamic on Mission: Impossible. Wade Eastwood [stunt choreographer] and his team are incredible. Working with Cruise was", she says, "a revelation. He does his own stunt work and sets the bar incredibly high."

Ms Ferguson was born in Stockholm and studied at the Adolf Frederik Music School and appeared in the Swedish TV series Nya tider. Her other TV work includes Wallander, The Inspector and the Sea and The White Queen.

Her films include Lennart, A One Way Trip to Antibes, Cold Night, The Vatican, Hercules and Despite The Falling Snow. She will be co-starring with Meryl Streep in Florence Foster Jenkins.

Mission: Impossible - Rogue Nation is out now.