Francesca Annis, now 54, is, with almost tedious regularity, compared to fine wine - she just gets better as she gets older, is the common refrain. But her phenomenal popularity coheres with a wider trend: for the first time, women of a certain age are being allowed to carry series on their own. Once they reach the age of 40, actresses are no longer being told by TV execs: "Sorry, love, that's your lot. If you're lucky, we might be able to find you a walk-on in One Foot in the Grave, but otherwise it's the Twilight Home for Retired Luvvies for you."
It all stems from what you might call the "Prime Suspect Factor". When Helen Mirren picked up audiences and awards by the police-van-load as DCI Jane Tennison in Lynda La Plante's groundbreaking 1991 series, commissioning editors finally woke up to the fact that a large proportion of their audience is made up of middle-aged women and that those people have interesting stories to tell. The execs' eyes lit up with signs reading "major-league ratings".
Before you could say "older woman", they were rushing to commission dramas spearheaded by the likes of Patricia Routledge (Hetty Wainthrop), Amanda Burton (Silent Witness), Pauline Quirke (Maisie Raine), Joanna Lumley (Coming Home), Pam Ferris (Where the Heart Is), Miriam Margoyles (Supply and Demand), and, of course, the grande dame herself, Helen Mirren (Painted Lady).
Annis is merely continuing the "woman of a certain age" tendency by headlining opposite Robson Green in a feature-length version of ITV's May-to-September romance, Reckless. In a key scene from the first series, her character, Anna, tries to get to the bottom of Owen's (Green) fascination with her. "What is it with older women?" she asks. "What do you find attractive about them?"
"I'm not interested in older women," Owen replies. "I'm interested in you." The inference - as in all these "older women" pieces - is that it is character, not age, that matters.
Sita Williams, the producer of Reckless, reckons that drama is merely reflecting the increased profile of older women in real life. "To my mother's generation, 50 was old, but now we've got spending power, we're very aware of our own independence and we have emotional and physical confidence. That's why Age Concern used that poster of a beautiful women in her fifties wearing a bra. More and more women boast about their age because they look and feel terrific. Also, women want to watch women of substance. You can only watch so many young things prancing about."
Beautifully turned out in a grey sweater and tight black skirt, and boasting exquisite skin and liquid brown eyes, Annis could almost pass for a young thing herself. But that's not the point. She is now being cast as her real age - and is delighted about it. In her opinion, this commendable move towards less ageist casting for women can be ascribed to a more flexible, open society. "Commissioning editors can see that there's more complexity to life these days. We've accepted that women can now be career women and mothers, and we've got a wider spectrum of views. Things have broken down in terms of social types. It's all up for grabs now - unlike the 1950s, when anything outside the stereotype wasn't projected.
"The more fragmented life is, the more fragmented TV becomes. People are very complicated and they don't have to be portrayed two-dimensionally."
This acceptance of new types of drama is all down to generational change, Annis continues. "In the 1960s, I was given my grandmother's trousseau. It was full of beautiful undergarments that came to me in immaculate condition. I wore the camisoles and petticoats as clothes out in the street, but I never wore them to visit my grandmother because that would have been inconceivable to her. In the same way, when I pick up my daughter's magazines now, I think `what?' It's incredible what they write."
In the past couple of years, Annis has also found much of what has been written about her incredible. Her relationship with Ralph Fiennes, who is two decades younger than her, had the tabloids hyperventilating with excitement. They gleefully ran any number of articles pointing out the similarities between life and art. She is the first to admit that "it was a publicist's dream that I should have been doing Reckless".
The F-word does not crop up during our interview - it has been expressly outlawed beforehand - but Annis does talk euphemistically of the "mayhem" that occurred when news of the affair first broke.
"It was an absolute, complete nightmare. I don't buy the tabloids, and I'm not a masochist, but, of course, you're surrounded by it all. I use public transport, and I'd be sitting on a train looking over someone's shoulder and thinking: `That's familiar... oh my God, it's me.' It's like being in a terrible anxiety dream."
So how could the actress find a quieter life? Might we soon be seeing Francesca Annis as Compo's new girlfriend on Last of the Summer Wine? Well, perhaps not quite yet.
`Reckless - The Sequel' is on ITV tomorrow at 9pm.