Sienna Miller: On Tabloids, Romances & Her New Fashion Line

Sienna Miller has been a tabloid target on both sides of the Atlantic. Now she’s ready to fight back and hopefully change some minds about her.

“What I do in my spare time is my business,” she told Access. “I’ve never been late for work, I’ve never missed a day work so what I do when I’m not working is what do and if they want to document and make it dramatic that their business.”

Sienna says her life is not at all like her tabloid reality – cast by some as a boozing party girl who hooks up with a roster of celebrities. Most recently she was rumored to be romancing Diddy and “The Edge of Love”co-star, married actor Cillian Murphy.

Sienna says it’s all rubbish.

“No, absolutely not,” she says. “I’ve been in two major relationships in my life and I was in a relationship when I was apparently sleeping with other people.”

Now, Sienna’s back on screen, starring as what else, a headline-grabbing star who gets into a verbal tangle with a cynical journalist [played by Steve Buscemi] in the drama “Interview.” Sienna does not think this role mirrors her own life.

“I don’t think it’s anything like my real life,” she said. “It’s maybe how the tabloids like to think my life is.”

One of the things that makes up Sienna’s real life is a new business venture with her sister. Sienna has long been a fashion star, helping spawn the boho trend and even taking away attention away from style maven Kate Moss in London fashion circles.

The Miller line will be known as Twenty8Twelve Sienna’s birthday (in her native U.K. they switch the month and day), and it’s due to hit the shops in September.

“Dickensian London was a real inspiration,” Miller explains of the collection. “Patti Smith [is also an influence] so it’s a bit rock and roll and a bit London and sort of little tailored jackets and stuff that I’d never really worn before like man’s trousers with braces and little cropped dresses and all sorts of fun things.”

One of Sienna’s favorite pieces from the line is a pair of pants she had a heavy hand in developing.PHOTO GALLERY: Sienna Miller

“I’ve designed some jeans that are sort of my babies that are sort of red with zips all the way up the back,” she enthused. “They’re quite hard core.”

Budget buyers, fret not. The Miller sisters’ line won’t break the bank.

“It’s designer diffusion prices, so not ridiculous at all, like 150 dollars for a pair of jeans,” she said. “That’s expensive, but it’s not designer level and then you can get a t-shirt for like 30 bucks, so it’s like, it’s affordable, I want it to be affordable.”

The girls plan to launch the line at Bergdorf’s and Neiman Marcus.