Helen Mirren is reluctantly submitting to a half-hour telephone interview to help promote her latest movie, “The Madness of King George.” No, she’s not embarrassed about her participation in the film – she loves it – it’s just that she can’t bear missing a moment of the O.J. Simpson trial.

“I adore Marcia Clark,” says Mirren from Los Angeles. “She’s my present-day heroine.” Suggest to the actress, who is best known for her tough-as-nails portrayal of a London policewoman on TV’s “Prime Suspect,” that she’d make a great Marcia Clark, should the prosecutor’s life ever reach the big screen, and Mirren laughs. “I think so too,” she says, “and, of course, it’ll be Winona Ryder. You know it will. Or maybe Melanie Griffith.” That exchange, at once funny and worldly wise, is pure Mirren. Known in her native England as a Shakespearean actress, she reinvented herself for the movies as the thinking man’s sex symbol. She scampered nude through films such as “Caligula” (1980), “Cal” (1984) and “The Cook, The Thief, His Wife and Her Lover” (1989). Then, along came “Prime Suspect” and Mirren’s career seemed to take another turn.

The British series, which will return to PBS for a fourth installment later this year, earned Mirren a Best Actress prize from the British Academy of Film & Television Arts and elicited dream reviews from critics on both continents. Now with “The Madness of King George,” a tragicomedy about George III’s bout with mental illness which opened yesterday at the County Theater in Doylestown and bows Feb. 24 at the 19th Street Theatre in Allentown, Mirren has switched gears yet again. As George’s adoring, long-suffering wife, Queen Charlotte, she wears big dresses and even bigger hair. That’s quite a departure from the tailored suits and short ‘do of her “Prime Suspect” policewoman. “Absolutely,” agrees Mirren, 48. “I loved those costumes. Loved them. I was so sad the day I had to take off my court gown and never wear it again. It weighed a ton, but I didn’t mind. I’ve got a real Barbie-doll attitude toward life. I just love big hair, frilly clothes and lots of sparkly things.”

Mirren was so convincing as a royal that during an early morning shoot outside London’s St. Paul’s Cathedral, some passersby got the wrong idea about all the pomp and circumstance. “We had to do this one shot of us going around and around in our royal carriage — you know, that little pink-and-gold coach,” says Mirren. “We had a lot of extras shouting, `Hurrah! Hurrah! God Save the King! God Save the Queen!’ And as time went on the Japanese tourists started arriving, and they’d start joining in. I think they thought we were the real thing.” To prepare for her turn as queen to Nigel Hawthorne’s king, Mirren studied royal portraits (“They didn’t reveal much because they were so formal and calculated”) and read extensive accounts of King George III’s life. As history buffs know, his reign was a turbulent one. After “losing” the American colonies, he suddenly went mad and had to be institutionalized. While Mirren couldn’t personally identify with the queen, she ended up respecting the woman’s never-ending devotion to her sick (and nearly-overthrown) husband. “I got the impression she was a really nice person — very sweet, warm and generous,” notes Mirren. “Not demanding or regal in that sense.”

And what about the royal marriage, which yielded 15 children? “It was a love relationship in every sense of the word, which is very rare back then or, really, at any time.” There’s been talk in the British press that Mirren might soon be made a Dame on the queen’s honor list, the equivalent of a gentleman’s knighthood. “No way!,” she laughs, “Can you imagine? I would happily become Countess Helen Mirren. Or Princess Helen Mirren. But Dame is such an awful phrase.” Somehow, the title detective chief inspector seems to fit Mirren much better. As DCI Jane Tennison on “Prime Suspect,” Mirren is at her best. Her natural strength and grit seem to filter perfectly through the workaholic cop. “There’s a lot of me in her. But I’m very different from her. I cry more. A lot more. And I wear much higher heels than she does.” Asked if Tennison is the performance she’s most proud of, Mirren lets out a long sigh. “I’m not proud of any of them. You’ve got to go on, and the only way to go on is by thinking you’re not good enough and that you have to be better. I haven’t seen lots of things that I’ve done and, to tell you the truth, I’m not interested.”

Recently, Mirren fans were outraged when Universal Pictures announced it had bought the film rights to “Prime Suspect” with plans to mount a big-screen version starring a younger actress in the lead role. If Universal re-considered, would Mirren be willing to repeat her performance? “I hate talking about this,” she bristles. “It’s impossible for me to answer that question because I don’t know if I would or I wouldn’t. I haven’t read the script, nor do I know who the director is.” In the meantime, Mirren signed up for two more two-hour episodes of the series. “They’ll be dark stories again, up-to-date stories about our modern-day society.” Mirren might be best known for her portrayal of the no-nonsense Tennison, but she’s no fan of cop movies. In fact, she says she draws her inspiration primarily from athletes and singers, especially Judy Garland.

“She inspires me constantly,” notes Mirren, whose credits include “The Mosquito Coast” (1986), “The Company of Strangers” (1991) and “Where Angels Fear to Tread” (1991). “Her commitment and energy and passion are amazing. She throws herself so wholeheartedly into (her music) that nothing else exists.” Among Mirren’s favorite actors are Paul Scofield and — drum roll please — Doris Day. “I think she’s great. She’s one of the most underestimated talents in movie history. I was never into her as a singer, but as an actress I think she’s better than, say, Greta Garbo, who is always so wooden and affected.” Mirren divides her time between London and Los Angeles, where she’s lived with her “White Nights” director Taylor Hackford for nearly a decade. In the past, she’s been linked to Prince George Galitzine, a Russian aristocrat; photographer James Wedge and the then-unknown Liam Neeson. In some Neeson biographies, Mirren is credited with helping the actor get seen by the right people. “I didn’t discover Liam,” snarls Mirren, who will make her Broadway debut this April in Turgenev’s “A Month in the Country.” “We lived together and were very happy together. It’s true that (in the early ’80s) he wasn’t a successful, famous film actor, but I didn’t discover him or nurture him or support him. We just had a nice time together.”

As for Hackford, Mirren calls him a “great guy,” but insists they have no marriage plans, nor any desire to work together again. Does Hackford ever offer Mirren any acting advice? “Oh, God, no,” she shouts in mock horror. “I can’t be dealing with advice. Loved ones are there to give you unconditional admiration because, let’s face it, no one else will.”