'Life goes by so fast, doesn't it? Now there's not that much time left. I've got so much less life than I've had.' Sheila Hancock is 67, a mother, a grandmother, a steadily working woman. She lost her first husband. She has had cancer herself. 'Life's never just smooth,' she says. 'Don't ever expect it to be.' She has been an actress for more than 50 years, since she was 15 and played Beth in Little Women. She has been in Carry On films (she was, apparently, the only woman Kenneth Williams would allow to use his lavatory), in sitcoms, in Hollywood films. She had her own TV slot (Now Seriously, it's Sheila Hancock). She was in the Actor's Company at the National Theatre, a member of the Royal Shakespeare Company. She electrified in Sweeney Todd, in The Duchess of Malfi, in Gorky plays. As she says herself, people don't know whether she is a straight actress or a comedian, or what. 'They're confused. They say: "When are we going to see you back on telly?" If you do theatre, most people think you've died anyway. But I never had a career plan; I wasn't lucky enough to be that revered. I've just always been a working actress.' Most recently, she's been wacky and relaxed on Have I Got News For You , where most women get eaten alive (the secret is to be yourself, she says). On 6 July, she makes a cameo appearance on EastEnders. And she is currently making a film, directed by Nick Renton, called The Russian Bride; she plays the mother, with a rich past and exotic hair and make-up. It takes her an hour and a half to get ready each day, and when I meet her, there are still traces of greasepaint on her creased, triangular face.

She sits in an easy chair opposite me, kicks off her shoes, coils her slim legs, uses her long and slender hands with great animation, pointing and gesturing, and occasionally laying her fingers against her cheek in an expression of delightful astonishment. She is constantly mobile and animated. Her eyes shine under their dark brows. She has strong opinions, high passions, great affections. She likes, she says, to be 'entangled' with life; she never wants to waste it ('It's the only one we have, after all'). Her husband, the actor John Thaw (Morse, Kavanagh, grumpy, ageing sexpot) once said that she jumps into situations feet first, and only then realises there's a 20ft drop. Now, she says, she is 'trying to prepare for old age' - by which she absolutely doesn't mean trying to learn patience, serenity, invisibility, sweetness, or that slow withdrawal from turbulent life that old women especially are supposed to go through. Quite the reverse. 'Old age for women,' she says, 'is often so sad. It's such a waste. I'm a Quaker and I tell you, I meet lots of splendid old women there, in their nineties some of them. They are the sparkiest, most intelligent, most enlightened women I've ever come across. If I campaign - well, shout my mouth off, really - about older actresses being overlooked, it's because I regard it as a duty. If they're being overlooked on screen, then they're being overlooked in life too. Older women being preposterous, witty, difficult. Women with grey hair having sex! You have to look younger than your age; you're only a splendid old woman if you look 20 years younger than you are. How do you break that down? It's a battle.'

Her own face carries its 67 years of experience: it is vital and kind and curious and sexy and wry with age. She doesn't wear make-up ('but that's partly vanity anyway, because foundation gets in the cracks'). She won't have cosmetic surgery: 'I don't want to spend my old age pretending to be younger than I am. But I don't like sagging. The pull of gravity is hard to resist. I work out. And I want my face to be tidy.' She grins. 'A neat and tidy face. It's better than it was,' she continues. 'There are fabulous women doing comedy now, too - grotesque comedy even. God, not like when I was young. The battles when I tried to be extreme, or radical, or controversial - anything that wasn't ditsy Sheila, working-class Sheila. Everyone,' she says, sitting up in her chair with her bright eyes and speaking hands, 'everyone has to trailblaze.'

Sheila Hancock grew up in London. Her parents worked in pubs. 'My bedroom was above the bar and it was quite rough, lots of noise. I would lie there listening to this strange, mysterious clattering going on, shouting.' She was seven at the outbreak of the war, living first in King's Cross and then Bexley Heath ('Bomb Alley'). At eight she was evacuated to Berkshire. The local children 'resented us. We were quite bullied. I can hardly bear to think of it now - being put down in a strange place, away from our parents, or else living our life in London down holes really - sleeping in a shelter, having a lesson in a shelter, walking around in helmets and gas masks. I think that I am now a basically fearful person. There's a core of fear inside me. It's always there.' She spends her time with her grandchildren telling them how beautiful and bright and tremendous they are. 'So that they maybe won't be fearful like me.' She loves fearlessness and honesty and confidence - Germaine Greer is one of her idols, for her 'courage in this time of hype, of culling, of taking the middle way. A stunning woman.' Her own fearlessness - the engagement with life that John Thaw talks of, that makes her active, vociferous, candid - doesn't come naturally to her. It's a willed and plucky quality ('I've learnt my style from magazines,' she says). She's valiant.

Hancock's childhood fears make it surprising, perhaps, that she chose to become an actress (she has always suf fered from excruciating stage fright, which she now copes with by seeing a hypnotist). 'There weren't that many choices when I was young, not for someone like me.' She loved her grammar school, where she won a scholarship, and was inspired by many of her teachers - 'but I didn't want to be a teacher, or a nurse, which seemed the only other options. Then I was in Saint Joan at school and people were nice about it and I thought I'd try.' She went to Rada, and then 'disappeared into weekly rep and obscurity for years on end. I slogged around. Nobody noticed me. When I was young, my sort of person didn't fit in. I wasn't pretty and I had a bit of an accent. I've never felt,' she says, without any trace of false modesty, 'that I looked any good. All my life I've felt plain. Sometimes I look at photos of myself when young and I think, "Well, I don't look bad really, I've a good figure."'

I ask her what on earth she dislikes about her appearance. 'My chin,' she touches it. 'My chin's too big. And my nose,' she puts a finger to her nose, 'my nose is funny. I love beautiful women,' she says. 'I'm not jealous of them at all. I remember when I was at Rada, with Diane Cilento. I went to her flat, and she took a bath. She had skin like a peach and green eyes and blonde hair. I almost wept with pleasure when I saw her, she was so lovely. I was this plain version of her, which is probably why I was so moved by her. I like beautiful men too. I would have loved to have been beautiful; to have looked in the mirror and said: "God you look wonderful." Do people do that, I wonder. Love what they see in the mirror?'

In her late thirties, her father died. 'That hit me hard. His dying changed me. I was always a girl who wanted to please her dad, and he so wanted me to succeed. 'If I came home and said "I came second?" he'd say "Who was first?" I was a grammar school kid and my parents weren't educated. I look back with enormous regret and pain at that time in my life when I grew away from them. I didn't despise them exactly, but I felt, well, grand, superior. My father died very suddenly, before we had time to say things. My mother died a year later, of cancer, and we came back to each other before she died. I nursed her and in the last few months we were very close. We don't tell our mothers we admire them enough, do we - or I didn't. She wasn't a woman who talked easily about her emotions. I remember washing her one day and saying "God Mum, what a lovely nose you've got." She said, "All my life I've hated my nose." [Clearly, the anxiety about noses runs in her family.] I thought, how is it I've never told her before how beautiful she is. Her lovely nose.'

A year later, Hancock's first husband, the actor Alec Ross, also died of cancer, a long, drawn-out death. 'It was a nasty period, yes. There was a lot of suffering - for them,' she adds hastily, not for her. She coped with the grief and loss by getting involved with the hospice movement. 'You've got to allow yourself the sorrow and then you've got to be practical. I thought: "I'll do something with these feelings." But this is just life,' she says - everyone's life. She's no different, except she is luckier than most people, with money, security, family, a job she loves. 'Life is not continual joy for anyone. Life is something that has to be lived and [she wrinkles up her nose] achieved. We have to earn our right to be here. Interspersed with the struggles are the glorious times. But they cannot be continuous. If you are a thinking person, they cannot be. Even when you are having a wonderful time, you must know there are others who are suffering. Life is not a bowl of cherries. It is a series of things you get over and survive - if you're lucky enough. Some people's life is made up of suffering. I worry when I come across people who expect life to be just happy, who expect to be beautiful and healthy and successful and perfect. Life is a hill you must climb. Just take a deep breath and do it.'

Even after those three deaths, Hancock 'always had hope. There's a working-class steeliness in the middle of me, a will to survive.' In 1973 she married Thaw, and they are married still, with three daughters between them, grandchildren whom they adore, a house in France, a cottage in Wiltshire, a flat in London, but, she says, 'a rackety old domestic life really. We work terrible hours.' She insists on their 'ordinariness'. She says they are blessed. Sometimes, she says, they look at their lives and feel proud of how far they have come. 'John'll say: "Well, a bit of a change from the council flat." It can feel unreal. We don't take it for granted, not at all, not for a minute.'

Twelve years ago, Sheila Hancock had breast cancer. It did not, she says, 'ennoble' her, but it did teach her to make the most of whatever time she had left, 'although that's simply from getting older, as well. You learn to savour life. You look at a sunset and you realise how wonderful it is. You give yourself the time.' Cancer, she says, with all its attendant pain and fear, was 'nothing, absolutely nothing, I can't even think about it', compared to the emotions she went through 18 months ago when her grandson, Jack, had a brain tumour. 'We could have lost him. Anything else pales into insignificance. I lose a job, so fucking what? Cancer - huh. I couldn't do anything, boss the doctors, make arrangements - that wasn't my job, that was my daughter's job. I could only be there if I was wanted. Crying and praying and waiting. It's the closest I have ever come to not being able to cope.' She puts her hand over her mouth and stares at the memory.

She wants to go on working. She wants to learn the piano ('but I want to be brilliant - first not second'). She wants to write a novel (she has the first three chapters but calls them 'crap'). She has just built a sandpit in her garden for her beloved grandchildren. She still has her centre of fear. She remembers once taking part in a show called Night of a Hundred Stars. She was waiting in the wings with Millicent Martin. 'I was dying with fear. I said to Millie, 'Aren't you scared?' and she said 'No, why should I be? I wouldn't be here if they didn't want me.' And she went on and was marvellous and I went on and I was ghastly. I loved her spirit. I love that kind of confidence in women. I have a friend who knows she's pretty, and wonderful. Her parents told her so all her childhood. It's a joy to be with her. She bubbles with pleasure. So in the moment. She's never whingeing or saying, "Oh, am I all right?" It must be so tiresome to be with me. People must get so impatient. I bet they want to shake me and shake me.' I don't think so. Hug, maybe.