Amelia Warner - Lorna Doone finally gets what she really wants

As an actress, Amelia Warner had it all. So why did she jack it in to sing cover versions of Eighties hits? She tells Charlotte Cripps

New beginnings: Amelia Warner, who now goes by the name of Slow Moving Millie

The singer Slow Moving Millie, aka Amelia Warner, 29, is perhaps best known for her lead role as Lorna Doone in the BBC costume drama of 2000. She also hit the papers when, a year later, at 19 years old, she "married" actor Colin Farrell, in a non-legal ceremony on a Tahitian beach.

"It was either that or shark feeding at the reception desk of the hotel," says Warner meekly when we meet. "It was just a man holding a shell. Colin and I wore skirts." Although the couple were engaged at the time for real, they split up four months later. "Like any first love it ended in tears and heartbreak," Warner adds.

But despite her acting past most people will have heard Warner singing recently without even knowing it. Her cover of The Smith's "Please, Please, Please, Let Me Get What I Want" was picked up by John Lewis for their Christmas advert after Universal Music submitted the song. And now Warner – who also played Michael Caine's child bride, in Quills, at the age of 18, has put acting firmly behind her.

Instead she has just released an album of covers, Renditions under the name of Slow Moving Millie. It features her stripped-back versions of Eighties hits, with her on piano. Songs include Bananarama's "Love in the First Degree", Black's "Wonderful Life", and "The Power of Love", which was made famous by Frankie Goes To Hollywood. Despite her delicate and hauntingly beautiful voice, you can't but help crave the original version of the song. Luckily, then, she is in the studio recording her debut album of her own songs, which she describes as "dramatic", "orchestrated with big arrangements", and "busy" with a "cinematic soundtrack" feel to them. Two of her own songs are on the Renditions album ("Beasts" and "Hart with a Crown & Chain") to give a taste of the magical, fairytale world of her music. Warner who signed to Island Records a few months ago, is currently playing about with forming a band.

"It is just me alone with a piano at the moment", she says. Her musical influences include Tim Burton's films, as well as music by Rufus Wainwright and Randy Newman – because of "the storytelling in their songs". Very shy in person, Warner, who has a vulnerable quality to her and is wearing a vintage orange coloured blouse and floral silk miniskirt – has expended an enormous amount of energy overcoming her phobia of being in the limelight – a strange problem for a performer.

"The constant pressure of having to prove myself as an actress didn't sit well with me. I got fed up with acting because my heart was never in it. I'd be in LA auditioning in front of 30 people. The feedback that I always got was that I didn't want it," she says. "I was up against lots of actresses who would fight tooth and nail for a part but I didn't have the passion. I didn't want to suffer through the moments of nervousness. I felt exposed and judged all the time. So I thought it was best to get out. Music is my soulmate but that's what stopped me from doing it for so long. I felt like if I get judged on this that would be devastating. But at least I have the passion to get through it."

Born in Liverpool in 1982, her parents split when she was very young. The only child of actress Annette Ekblom, who was in the original West End cast of Blood Brothers, Warner and her then-single mum moved to Ladbroke Grove, West London, when she was four years old. She went to the Royal Masonic School for Girls and also won a place at the Royal Court's youth-theatre group. At 16, she went on to do her A-levels at north London's College of Fine Arts, when she landed the role of Lorna Doone, alongside Richard Coyle, in the romance set in the wilds of Exmoor during the late 17th century. That same year, at the age of 17, she was cast as the child bride who gets corrupted by the Marquess of Sade in Quills.

"I was thrown into the deep end but I hadn't expected any of it," she says. "It was overwhelming and when I was on set it was the moments when my scene was being filmed that I disliked the most. To be an actress felt wrong; I don't know why that was. I thought I was so lucky to have the work but was never happy."

Warner did 12 films after her first small part in Mansfield Park in 1999, as a teenage Fanny Price. She played Charlize Theron's sister in sci-fi thriller Aeon Flux in 2005, when she was 23. Other notable film roles included the American drama Winter Passing in 2005, about a depressed bartender/actress played by Zooey Deschanel, who discovers her dad (Ed Harris) is a famous novelist who has taken Warner's character, a student, under his wing. Then, in 2008, at the age of 26, Warner gave it all up to pursue music. To friends and family, Warner has always been known as Millie, destined to be a singer.

"I spent so much time figuring out what I wanted to do that the name Slow Moving Millie is a joke because I am so slow to work it out. Having been an actress, this felt like a different part of me. It is a separate identity." For the last few years she has been writing songs and finding her calling in life.

"When I got signed to Island Records a few months ago, it was a relief. It was scary walking away from a job that was making me money. I was scared I'd regret it – but this has proved to me that it wasn't crazy to throw it all away."

Why did she chose to sing Eighties music? "I think Eighties music can get a bad rap because of the naff way it was produced," she says. "The lyrics are really dark, but are trussed up in these manic assaults of melody and sound. But underneath they're actually all really poignant songs, and they're all about having your heart broken."

'Renditions' is out now