THE NATION looked in wonder at the sixteen year-old X Factor finalist.

And it wasn’t because Diana Vickers had a hippy-dippy ethereal quality about her, that she stood on stage in bare feet and evoked memories of Sandie Shaw and the sixties.

It was because the young lady from Blackburn had a real, rare talent.

Now, eight years on, Diana is giving of a very different type of performance, playing the perennial virgin who manages to discover her inner vixen.

Diana is set to star in the latest incarnation of the Rocky Horror Show. And in case anyone has been on Mars since its creation in 1973, this forties-style horror B movie homage tells the story of Brad and Janet.

The two squeaky clean college kids come across a haunted house and its occupier, Dr Frank N Furter, a creature determined to sexually liberate the planet.

It’s a musical so camp it’s a wonder no one has built a music festival around it. But then it’s a music festival of its own, of course with iconic songs such as the Time Warp and Sweet Transvestite.

How can Diana slip into the Doris Day-like lead role as Janet, the innocent lost in the world of sexual deviation and . . ?

“Janet is so me,” she says, laughing. “I guess we all have an innocence about us, and Janet is easy to play in that she’s all bright eyed and bushy tailed and quite nervous.

“She’s easily led, which I am, and she is easily seduced, and I like the journey she goes on.”

In what ways is Diana Vickers easily led?

“Here’s an example; I went in for a haircut the other day, with strong ideas of what I wanted, pictures and all. But the hairdresser said ‘No!’ I want to cut your bangs’ and I and I went along with that. I’m quite suggestible.”

Actresses with insecurities isn’t unusual. In some ways, it’s a positive in that they are constantly searching for a character outwith their own.

“That’s true,” says Diana who has had reason to have a few self-doubts, having swam through the shark-infested waters of the record industry, having argued with the record bosses about the sort of material she should record.

She made it to the other side, despite being hyped up and dropped after her reality tv publicity waned; the usual reality tv show reailty.

“Showbiz has toughened me up along the way,” admits the 25 year-old.

“I used to let criticism get to me. When I was younger I’d get comments made about my appearance, my weight. I let it get to me, not realising your body changes a lot.

“But I’m okay now. And I’m northern, which helps.”

She adds, with a self-satisfied smile; “What helps was at least I knew the style of music I wanted to do. There are a lot of tough businessmen in the industry, who think they know best but I was able to speak out and stick up for myself.”

Despite having a delightfully idiosyncratic voice, Diana didn’t grow up wanting to be Joni Mitchell.

“No, I love Joni Mitchell but I always wanted to become an actress,” she maintains.

“I always wanted to get into musical theatre. I did musicals at school and attended drama school, and I wanted to go to drama college and work in the west end and TV.

“I had a dream about being a pop star, yes, and when the opportunity came up I had to take it.

“But I couldn’t take the pressure and the point came I didn’t want to be a pop star anymore. I got a bit disheartened. One minute you’re all over the radio, the next is gone.

She adds, in more serious voice; “A big problem was I had to maintain this persona all the time, it was all about remaining in character, the same character, and that’s not me at all.

“As an actress I get to play different roles. I want to act more, maybe do something dark. And I did two TV series and I loved it. I want to do more comedy. I want variety.”

Did her pop management try to make her sexy, do FMH covers?

“Well, I did FHM, but I wore more clothes,” she says, grinning, indicating she wasn’t physically dragged to the photo studio. “And I tried to make it artistic.”

What’s pleasing is that the former pop star didn’t come out of the experience penniless, having had a No 1 single and album.

“I got a great publishing deal, and I wrote both my albums. And yes, I got a good deal.”

She adds; “I was protected by my management company. I never felt too vulnerable.”

The profile from the music career has allowed Diana an easier access to musical theatre.

She has already starred in Little Voice and west end play The Duck House. I still sing the medley in the shower, try to keep it up. It’s my party piece.”

But she admits touring theatre has been tricky to adjust to.

“I’m quite a home bird and I found touring difficult at first. I miss my sister and my friends. And you have to get used to each new city. But I’m getting there.”

When offered the Rocky Horror role, Diana was unsure about how to break the news to her parents.

“My mum and dad had been to see it and it wasn’t their cup of tea. But when I was seventeen I watched the film and thought it absolutely bonkers, and great fun.

“I didn’t quite understand all that was going on, but it was really fascinating.

“Then when I went up for the role of Janet and got it my mum completely changed. Now, she is totally converted.”

There is only one little difficulty Diana has experience with the show.

During the performance it’s become standard for the audience to yell out comments, (a throwback to the movie version, when the Narrator was so slow the audiences would yell out to fill in the gaps) most of them unprintable.

Diana, at times, can’t stop the giggles. “Once you hear what people are capable of saying, you just go,” she says grinning.

“There is very often no way back.”

• The Rocky Horror Show, The King’s Theatre, August 8-13.