Mirren tops the league table of actors who take their clothes off in mainstream movies, according to Craig Horoda, author of The Bare Facts Video Guide. The guide helpfully lists and details every nude scene to have appeared on screen. Horoda notes that for every male screen strip there are three female strips. But Greta Scacchi, number two in the league table, is one actress who has had enough. Announcing that her days of on-screen stripping were over, she explained: "I don't want to be known for throwing off my clothes at the drop of a hat."
Meanwhile, younger stars may be seeking this very reputation. When Minnie Driver auditioned for the James Bond film, Goldeneye, she allegedly begged to be one of the naked, prancing women in the titles. Others agree to strip only on certain conditions. During the making of yesterday's steamy BBC Screen 2 drama, Loved Up, actress Lena Headey told her director that if she and co-star Ian Hart were to strip for the lengthy and explicit love scenes, it was only fair that the crew strip too. She was joking. So when she and Hart began to remove their clothes, she was surprised to see the crew join in.
"At first I thought `Oh my God, I feel sick, I think I've said the wrong thing'," she giggles, "but it did make it easier. When they said `Cut' it was us covering up, turning round and laughing at them for being naked - it balanced it out."
It's rare for director and crew to go to such lengths. In fact, they may attempt to take advantage of the actor's vulnerability. "Just because you've had nudity written into your contract doesn't mean you have to be bullied and made to feel under pressure," complains Headey who, like many actresses, has had to put her foot down in the past. She says that she always loudly queries the necessity of a scene she feels is too explicit. "I will remind the director that people have got imaginations, you don't have to be graphic for the scene to be effective."
For actors, both male and female, one of the most important decisions of their career is whether they will agree to appear in the buff. There is a constant demand for nudity, particularly on screen, and any actor who looks halfway decent may be jeopardising her (or increasingly his) career by refusing.
And for actors fresh out of drama school - where there is rarely any guidance on the nudity issue - drawing the line to a powerful director may be too daunting. Emily (not her real name), a young actress, relates how she was being pressured into a topless scene when she was saved by a crew member remarking that her breasts would be out of shot anyway. Clearly miffed, the director went for a slow close up of her cleavage instead. Emily, already feeling humiliated, overheard the cameraman comment: "Can you believe I get paid for doing this?"
Many actresses include a condition within their contracts that they will agree to appear nude as long as it is in the interest of the production. According to Equity, the actors' union, when it comes to nakedness, performers should be protected against any form of peer group or directorial pressure by the nudity clause in their contracts; no signing means no stripping. Recently director Michael Bogdanoff ran into contractual trouble while rehearsing Faust, his latest production for the RSC, when he suggested that some of the cast appear nude without having given them the option of a nudity clause.
But sometimes, apparently, appearing au naturelle is preferable to parading in suggestive clothing. Joely Richardson, whose own private parts will be familiar to anyone who saw Lady Chatterley's Lover, recalls the remarks of Juliet Stevenson, her co-star in Drowning by Numbers. "She said she felt fine about the nude scenes but when she had to wear a bathing suit and high heels and go down the stairs, she wanted to die. I felt the same way about Lady Chatterley. I would be mortified if someone asked me to put on a bikini and throw a beach ball up in the air for something sexist like Baywatch, whereas dancing naked in the rain seems perfectly natural," she explained.
It is not just women who run the risk of being exploited. During an audition for an apparently serious play, Mike (not his real name) was asked to remove his shirt. He hardly thought twice. But when he was offered the part, he was only sent half the script. Smelling a rat, he demanded the other half, and saw that not only was he to spend the second act in the nude but that the play was actually a sex comedy. "I don't object to acting in the nude per se. I'd be happy to do a play like Equus for example," he explains. "But in this instance I didn't fancy being caterwauled at by the audience."
Some actors see this as a fuss over nothing. Kevin McNally acted in nude scenes for theatre and screen during the Seventies and has no problems about appearing naked in the latest production of Dead Funny at London's Savoy Theatre. "When I was younger, I'd worry more about whether I was doing the sex right than the fact that I was naked," he says.
Some directors stoutly defend stripping off. Paul Verhoeven, director of Basic Instinct, describes his new film Showgirls as "erotic". It's about two strippers who become "lap-dancers" (a form of naked erotic dancing) and co-stars newcomer Elizabeth Berkley as one of the dancers. "It's quite unique," says Verhoeven, "to find a girl who can act, who can dance and who is not afraid of her own sexuality."
So: if you refuse to take your clothes off and act sexy it means you've got a hang-up. Widening this argument to include the audience, Verhoeven adds: "There is this absolute fear that people have about sex in motion pictures - I wonder what harm can be done if a 13- year-old kid sees this movie, goes home and masturbates? Maybe some people will fantasise about what they see or will try out something new with their partner. The point is that it won't hurt anybody."
Sharon Stone sounded a little naive when she said she was upset by the famous leg crossing scene in Basic Instinct because it "was much more graphic than I had expected". But actors can be taken by surprise. Helena Bonham Carter found that seeing her naked body magnified on a large cinema screen was a shock. Imogen Stubbs said of her first nude scene on television: "I burst into tears every time I thought of my family watching."
An assertive young actress like Lena Headey clearly knows where she wishes to draw the line. But if she had never agreed to appear in the buff, might she still be a struggling wannabe?
MEN WHO DO
Points: 2 for a rear view, 3 for full frontal nudity
1 Richard Gere 16 points for Looking for Mr Goodbar,American Gigolo, Beyond Limit, Breathless, Final Analysis
2 Sylvester Stallone 14 points The Italian Stallion, Tango and Cash, Rocky V, Stop! Or My Mom Will Shoot, Demolition Man, The Specialist
3 Jean-Claude Van Damme 12 points Bloodsport, AWOL, Double Impact,Universal Soldier, Nowhere to Run, Timecop
4 Gerard Depardieu 12 points Going Places, 1900, Loulou
5 Rutger Hauer 12 points Turkish Delight, Katie's Passion, Flesh and Blood
WOMEN WHO DO
Points: one for a rear view, two topless, three for full frontal nudity
1 Helen Mirren 32 points for Age of Consent, Savage Messiah, Caligula, Hussy, Excalibur, Cal Pascali's Island, The Cook, the Thief...
2 Greta Scacchi 28 points for Heat and Dust, The Coca Cola Kid, The Ebony Tower, Good Morning Babylon, A Man in Love, White Mischief, Presumed Innocent, Fires Within, Shattered
3 Amanda Donohoe 25 points for Castaway, Foreign Body, The Lair of the White Worm, Diamond Skulls, The Rainbow
4 Sharon Stone 23 points for Irreconcilable Differences, Cold Steel, Action Jackson, Blood and Sand, Scissors, Total Recall, Year of the Gun, Basic Instinct, Sliver, The Specialist
5 Melanie Griffith 23 points for Smile, Night Moves, Joyride, Body Double, Fear City, Something Wild, Stormy Monday, Working Girl, Shining Through, Nobody's Fool