JOANNA LUMLEY is giving herself an instant facelift, pulling back her perfectly made-up complexion to show what she would look like if she had plastic surgery. "A peeled orange!" she giggles. Then, she says, her face serious, she could put herself under the surgeon's knife and slash her head to ribbons – and she once thought she might.
But there would be no point, she says. "Everyone knows I'm 62, because I've always been scrupulous about my age. The idea of someone finding out that you've lied seems to me an extra anxiety we don't need in our lives. And remember, if you are going to be offered the parts of grandmothers, there's no point looking like a doll."
Right now, she's thrilled to be up for a meaty part for which she's been told she will have to age up. "Yessss! I can make myself look like an old crone. I had rat's teeth as Aunt Spiker in James and the Giant Peach, and I've been 102 as Patsy in Absolutely Fabulous, with prosthetics, in a wheelchair, on a vodka drip. So I don't give a damn about ageing!" she exclaims, before knocking on wood in the hope that she will pluck this particular plum – and, no doubt, plummy – role since it will also entail filming in India, the land of her birth.
Today, though, we're in the land of Lumley's fathers – and of her mother – talking over coffee at Edinburgh's Balmoral Hotel. In the capital to open the National Museum of Scotland's new exhibition, Jean Muir: A Fashion Icon – dedicated to the work of another woman who was proud of her Scottish roots – Lumley whispers, "Ah, Scotland," with a bosom-heaving sigh. "I am three-parts Scottish, and terribly proud of it, although maybe we should divide it into eighths, because my two-eighths are Danish and English, the Lumley part. But the bulk of the rest of me is Scottish – and Scottish ministers especially."
She explains, "My mother was a Reid, a good Scots name. Her parents married in Rangoon – as one does! Her father, Leslie Weir, was a Scot born in Ghazipur, and her mother, Thyra Sommers, a Dane born in New Zealand. My father's mother's name was Young. They were from Ellon originally," she says, pointing far north. "My great-great-great uncle – or maybe it's only two greats – crossbred the first Aberdeen Angus.
"And, of course, Jean Muir – who was my mentor because I didn't go to university, I went to work for her instead as her in-house model – was half Scottish.
"I think most of the world would like to be Scottish. All the Americans who come here never look for English blood or Welsh, only for Scottish and Irish. It's understandable. The Scots effectively created the face of the modern world: the railways, the bridges, the tunnels. It was even a Scot who discovered that if you didn't want to die of heat on the plains of India, you went up into the hills to a hill station."
Such is her passion for Scotland that Lumley and her husband, the internationally renowned conductor and composer Stephen Barlow, who is eight years her junior, have a home in the Dumfriesshire hills. They found the tumbledown cottage years ago, when staying with friends in the area. They retreat there whenever their busy work schedules permit. Previously, Lumley and Barlow – who married in secret at the register office in Fort William in 1986 – had only ever driven through the area on their way to the Western Isles. "That short stay showed us what is called Undiscovered Scotland – great bare, rolling hills, deep glens and rushing rivers."
Out for a drive with their friends, on a high hill they saw a little ruined cottage, which had been empty for 50 years – "and was beginning to crumble back into the land". The following day they walked back up the hill, battling a blizzard. "The wind blew mightily, but when we got up there in the freezing gale I suddenly felt warm and safe," she recalls.
"We share precious times there every couple of months. We always spend Christmas and Hogmanay in Scotland, and will do so this year. The most perfect times of all, of course, are when my beloved son Jamie and his wife Tessa and our two adorable small granddaughters, Alice and Emily, who are just heavenly, are there too. Stevie and I have quite a zig-zag existence because of our strange jobs, but we like to spend as much time as we can at the cottage. I can't wait for next October, when I'm judging a ploughing competition at Ellisland, the farm where Burns composed 'Tam o'Shanter'. Such a thrill!"
Seguing effortlessly, she asks, "Did you know that the bicycle was invented in a tiny Dumfriesshire village, Keir Mill, only four miles away from our cottage? The bicycle! Imagine! There is something so quiet and so industrious, something so Viking about the Scots. I love it! And having recently been to Norway (for the BBC documentary The Land of the Northern Lights], I found a huge link there, the way they talk about children and the words they use for them; barns, which becomes bairns here. I felt at home; I felt the tug, the pull of the north."
But then, is Kashmir-born Joanna Lamond Lumley not at home anywhere in the world? Even when abandoned on a desert island, with not so much as a toothbrush or a bar of soap, for the TV documentary Girl Friday, when she famously made a pair of shoes out of a bra? "That was the Scottish blood in me – necessity being the mother of invention. One of the greatest compliments ever paid to me was when I was on that desert island. We had an SAS man with us, just in case. I'd found an old tree trunk and just sat there waiting for them to start filming. He said, 'This is why you'll survive. You've made yourself at home – that's exactly what we do in the SAS,'" she recalls, punching an accommodating place for herself on the banquette of bolsters behind us.
"I remember thinking, 'I've got survival in me.' There was an old hippie song in the Sixties that rather shocked me back then. It said, 'If you can't be with the one you love, love the one you are with'. I've rather taken it to heart now. I don't keep saying, 'Oh, I wish I'd listened to so-and-so, done this, said that.' I suppose that's why I fight for the things I believe in. If you love something with a passion, it must come from within you. You are what you do, and you get what you want. That's why I'll always put my hand up."
Certainly, there is something about Lumley that is absolutely fearless. In March last year, she confronted a man with a gun in a Sheffield bar, calming him down with her ineffable poise and impossibly rich voice, defusing a dangerous situation by engaging him in small talk. "He didn't realise who I was. Anyway, I was in The New Avengers, I've handled guns," she said afterwards. The man received a four-month suspended sentence, and she says she's relieved he wasn't "banged up".
She pauses to thank the young waiter pouring her coffee with such charm that he walks away clearly having fallen head over heels. Of course, she'll always be a beauty, but she also exudes warmth, and there is a childlike wonder about her that is enchanting. And there is that voice: hushed and luxurious, like the sound of caramels melting, or silk rippling over velvet. "My voice wasn't always like this, although I don't hear it myself. It has deepened over the years. I used to sound awfully like this," she says, doing a high-pitched imitation of the Queen. "One did sound like the Queen when I was a gel, I'm afraid."
Currently, though, she is mastering a Scottish accent. With Simon Callow and Helen Baxendale, she is filming an episode of Lewis, the Inspector Morse off-shoot, which is due to be shown on ITV next year. She plays an ageing Scottish rock chick that the detective idolised in his youth. Once filming for that finishes, she is making another BBC documentary. "Martin Clunes did one about dogs, so this is the follow-up, about cats and their place in history, and cats around the world. It takes me to Cairo, Thebes and Namibia before Christmas. Then I'll be writing a book based on the series. It is all an awfully big adventure."
LUMLEY IS A tireless campaigner, charity worker and supporter of worthy causes – most recently that of the Gurkhas, some of whom the government had "shamefully" refused to let settle in this country. She chose to champion the plight of the Nepalese soldiers because her father, James, fought alongside them in the Second World War, and one even saved his life.
A daughter of the Raj, Lumley is all stiff upper lip and spiffing vowels, so she makes an eloquent activist. But she's also unusual in that she has become more, not less, visible as she has aged. "It's maybe because I haven't confined myself to acting," she says. "I've written books and, of course, I make TV programmes. Maybe it's because I'm interested in everything. Maybe it's because I write the letters. Maybe it's because I volunteer. Maybe it's because I'm always weeding the terrace. I was even weeding the terrace when Prince Charming – Stevie – stopped by on his horse. I don't sit around waiting for things to happen. But I do love acting still."
She's certainly a gifted performer. On stage, she has taken parts in everything from Nol Coward to Ibsen and Pinter, as well as playing the champagne-swilling, cocaine-snorting Patsy in Ab Fab, executing perfect pratfalls in a Chanel suit. "How I loved that show. Paradise! Heaven on a stick," she says. "We would be rolling on the floor crying with laughter. Too much fun! Maybe we'll go back to it one day. Everyone forgets, of course, that I started out in a sitcom, Jilly Cooper's It's Awfully Bad for Your Eyes, Darling, although for years, after Purdey in The New Avengers and Sapphire in Sapphire and Steel, I was perceived as this icy, reserved head girl. Obviously, I'm not at all like that." In fact, her comic timing is exquisite.
In last month's BBC1 documentary Ian Fleming: Where Bond Began, the erstwhile Bond girl who appeared opposite George Lazenby in On Her Majesty's Secret Service, informed us breathily that 007 "expects his woman to make a barnaise sauce as well as she makes love, though presumably not at the same time". She paused, and said, "Although I can and do. Frequently."
Small wonder that she is now universally regarded as a national treasure and is a frequent dinner-party guest of the Prince of Wales. "If she stood for election tomorrow," one columnist wrote recently, "I can't think she wouldn't win." Indeed, the morning after the Gurkhas won their High Court hearing and the right to settle in the land they had served so courageously, she was stopped by numerous well-wishers wanting to congratulate her on the victory. "Fabulous," she says, her blue-grey eyes shining at the memory.
"My job for the Gurkhas was to carry the flag up front. There were lots of people, teams of lawyers, who worked silently behind the scenes – wonderful people who were hell-bent that they should win their case. But I'm thrilled that four Gurkhas have just been given the Military Cross. The letters came flooding in when people found out how they were being treated. They are the bravest of the brave, the strongest, most inspiring troops, who gave us the guts to go on. I find it terribly moving that this country has found this stain on our honour unendurable."
"I AM A furnace of friendliness," Lumley once said of herself. Only half jokingly, she has also said, "I would give my coat to the first person that asked me, and they (the public] know that."
So, please may I have the coat off your back, I want to ask her. It's a 35-year-old brown Harris tweed, as chic as the day it was made – by Jean Muir, of course. "She was outside fashion, which is why this coat still looks wonderful," she says, snuggling into it for our photographer.
"The National Museum of Scotland exhibition is so beautifully done, it moved me so much. It's as if she's still with us. It proves that her clothes have never gone away. You could keep them for ever; they are timeless. I've a huge suitcase filled with Jean Muirs in the spare room, all neatly packed away.
"The little black dress I wore to the opening has been touring the world in an exhibition devoted to the LBD. It's one of many I own. I wore it with trousers last night because I am no longer 18, although many may be forgiven for thinking I still am!" she laughs.
"The second dress on the left as you enter the exhibition is a long black dress, with a half cape. Sensational! I've owned that dress since I was in my early 20s. I lent it to someone who was pregnant in her late 30. It's been worn by a woman in her 50s, and, more recently, by someone in her 20s. I'm much, much older, but I can still wear it today, because it was designed by an absolute perfectionist.
"Miss Muir – as she will always be to me – wasn't just about clothes. With her, it was to do with how you are in the world. For example, music was huge in her life, jazz and classical. I remember that she and her husband Harry took me to see Cabaret, with Judi Dench as Sally Bowles; then they took me to see Danny La Rue because she loved camp. Miss Muir also loved subtlety, and because she had a home in Northumberland, she had a passion for wildlife. Yet she was sooo-ooo sophisticated – and rather terrifying."
Lumley pauses thoughtfully. "I can't overemphasise the influence she had on me. Not just her flawless taste and rigid discipline and perfectionism in dressmaking, but her enthusiasm, broad knowledge, kindness and fearsomeness. She was frightening because she demanded the best from everyone."
Then she says, "Give me your hands. Miss Muir was quite small with fragile wrists. You have Jean Muir hands." I am not the first, nor will I be the last, person to walk away from an encounter with Joanna Lumley feeling absolutely fabulous.
• Jean Muir: A Fashion Icon, sponsored by Pagan Osbourne, is at the National Museum of Scotland, Chambers Street, Edinburgh (0131 225 7534, www.nms.ac.uk), until March 15. Admission is free
In praise of Jean Muir
"She seemed the distillation of modernity"
– Hamish Bowles, American Vogue's European editor-at-large
"Truly, she was one of my favourite designers. She was not about spectacular effects, but the look was strong by itself. It was pure, very simple and disciplined. Very strict and yet feminine"
– Jean Paul Gaultier, designer
"Women who define themselves in public by their appearance turn to her clothes with ecstasy and relief"
– Lady Antonia Fraser, writer
"I was in love with her image, her persona and what she stood for"
– Jasper Conran, designer
"Looking like a Sicilian widow and sounding like a demented corncrake"
– Sir Roy Strong, art historian