Actress Julie Walters is huddled on a large sofa. On entering the hotel lounge, all that is visible of her is the top of her head and her stockinged feet. The feet are on the low coffee table before her. It is as if they have been abandoned. "I'm a bit knackered," she says, smiling, motioning to her feet, and adds she has just arrived from Belfast where her latest movie, Titanic Town, premiered the night before. She is small and lively and very normal. There is no glamour, no temperament. For once, everyone is right. Julie Walters is genuinely engaging and very funny.

Hilarious in fact. Even the most random remark is hugely amusing. Comic timing comes as naturally to her as breathing. Where does the comic actress end and where does the private person begin? "I played Lady Macbeth in that play with Bernard Hill in 1985," she pauses thoughtfully. "I based her on Margaret Thatcher." Is she kidding? All serious: "You know the way she always knew what she wanted and went for it regardless?" Leaning forward, she smiles so deeply her small brown eyes disappear. She has a short-sighted peer, which may or may not have anything to do with her sight. That peer is famous: she can summon endless variations of it - and has, in various roles. The other thing is her accent. She begins the conversation in broad Birmingham, like a character from Brookside, and continues in these tones. But then, for all I knew she could have sounded like a member of the Royal Family. Walters is such a good mimic, and has played so many regional roles, it leaves one wondering where she actually does hail from. Such a comment makes her laugh. "In London, people think I'm from the North - Lancashire or somewhere. Up North they . . ." - pause - "well, they don't know what to make of me, but I'm from Birmingham." She deliberately stretches the word so long it takes a while for it to come out: "The midlands."

Interviewing actresses usually means forgoing questions about dates of birth. Walters entertains no such reticence. "I was born in 1950, so I'm very old. It's probably on the Internet," she makes a face before her face returns to its habitual expression, a concerned smile. At any minute, one feels, she could metamorphose into the old lady from Victoria Wood's Acorn Antiques.

She was the youngest of three, an only girl who followed two brothers after a gap. "We're working class Birmingham Catholics. My father was a builder and decorator. He was like the father in the film, always ill, exhausted. He's dead. My mother worked as a clerk for the Post Office. She was quite clever and had ambitions for us. She's from Mayo. Very dark. One of the black Irish: it seems the Armada sank off the Irish coast and there's all these Irish people like my mother, with black eyes, black hair and dark skin." Henceforth, each time Walters quotes her mother it is done in an impressively convincing Mayo accent.

School for her was not a success, although she was good at sport - "I was the Worchestershire Schools 200 metres champion" - including hockey. "I liked English. But no, I wasn't brilliant at school - in fact, I was asked to leave. The nuns decided I was `subversive'. I was a bit puzzled by this as I didn't know what it meant, so I looked it up and yes, well, I have to admit I was rather impressed."

There were few opportunities for acting at her Birmingham convent school, though she did discover her gift for impersonation. "I was always mimicking the teachers - `do this nun', `do that nun' and I was always being told `Oh, you should be on the stage'."

At home it was the same; " `Go on, do Auntie Mary'." Why acting? Walters looks thoughtful and says: "I suppose the usual reasons - insecurity, feelings of inadequacy, wanting to hide behind other people's personalities and so on." Then, as if she has just remembered something useful, she mentions: "I think it is also genetic." So who else in the family acted? "My grandfather, he used to recite famous court cases, bored the rest of the family silly. But when there was no television, it was a form of entertainment. And my mother always had quite a sense of drama." She launches into a Mayo accent: `Oh no, that girl'll come to no good' - and she had all the gestures." It was Mrs Walters who decided her daughter would "go in for nursing". Julie Walters laughs outright and then, assuming her mother's voice, reasons: " `She's not academic, so we'll get her into nursing, that's respectable.' "

Walters began her nursing training: "I can't exactly claim I had a vocation - all the time I was doing it I was asking myself `what am I doing here?' but I carried on and passed some exams. After about two years I was wondering `Am I going to be here for life?' " She left. "I was 21 then." Back home the reaction was predictable. "My mother was horrified." Outraged Mayo tones confirm this: " `She'll be in the gutter,' " and further lamentation.

She needed five GCEs to enter Manchester Polytechnic to study drama. "I only had four but took a fifth one in physiology which I had studied as part of my nursing training and I passed it." The audition was memorable. "The part I did as my audition piece was actually for a male character. Afterwards they asked did I not know? I said no, but it didn't matter." Work seems to have come quickly to her. But two factors proved vital to her success. "Doing Educating Rita and meeting Victoria Wood, she's a genius. I love her comedy, I understand it. We met in 1978 doing a revue. She was writing all these funny songs and they were brilliant. But there was a space to fill, so she wrote a sketch and I did it."

Considering that Walters can transform herself without the aid of a costume, and is capable of becoming a wizened old lady just by standing differently, does she find her comic flair overshadowing her serious acting? "No, I've never felt a tension between the two. I've always thought I was lucky in that I have both. I like the stage and TV. Comedians are often the best straight actors, they bring an understanding of life to a serious part. Comedy and humour are about life and about understanding human nature."

For all the gags and comic asides, she is an easy-going character, pleasant and at ease. There is no pretence, she is not involved in mystique. "What I want from acting, or from an actor is `can I believe it?' I think that's what decides it. It can't be too mysterious, or then no one will understand it."

She has created a range of characters: admittedly, some are far more bizarre than others, where do they come from? Does she observe people? "Not intentionally. I'm not particularly observant. I'd say I absorb things without noticing and then suddenly call them up."

In playing the hairdresser heroine of Educating Rita, for which part she was nominated for an Academy Award, Walters says she drew on her own experiences. "I was Rita, we had a lot in common. I was like her, from a working class background and I wanted something different." Referring to her part in Titanic Town in which Walters plays Bernie McPhelimy, a working class Belfast Catholic mother determined to protect her children, she says: "I based her on my mother."

Walters plays the lead in a movie in which most of the cast, including Ciaran Hinds, is from Belfast. How intimidating was mastering the accent before a cast of natives? "Very. I have no problem with a south of Ireland accent, it comes from the front of the mouth." And she demonstrates. "The Belfast one is trickier, it comes from the back."

The film, which is set in Andersonstown in 1972, was shot in London and Belfast. "Obviously we couldn't film in Andersonstown. It would be too insensitive. The memories are too recent: but I think films like this are useful, they make people think and anything that makes you think has to be worthwhile." Did she know much about what was happening in Northern Ireland in the 1970s? "Well, I had seen the news reports. But if you're an outsider, you can't claim to know. But yes, I suppose it is a bit strange having an English person come in and play Bernie."

What struck her most about the script was the way it was understood that the people were not allowed to have any opinions. "The ordinary citizens couldn't question the soldiers or the IRA, they had no rights, they couldn't challenge anything. They couldn't have an opinion about anything."

Based on Mary Costello's novel with a screenplay by Anne Devlin, Titanic Town is the story of Bernie McPhelimy, a housewife who refuses to put up any longer with the random shootings which are threatening lives in the housing estate on which she lives. Brave and determined, she is also naive and a bit vain. There are comic moments and at times one senses Walters had to concentrate on underplaying the part to let some silences in.

She talks about the gritty, North of England world evoked in Alan Bleasdale's outstanding drama, Boys From The Black Stuff - "The two Alans, Bennett and Bleasedale, I love their work." She has also appeared on stage in Bleasedale's Having A Ball as well as Tom Stoppard's Jumpers and appeared in a production of The Birthday Party in which Harold Pinter also featured, while her performance in Sharman McDonald's To Scream And Shout helped her secure the title role in Educating Rita. "I love theatre but it is difficult with a child."

Walters lives with her husband and their daughter in the Suffolk countryside. "It's an organic farm and we have sheep and pigs. Now we have about 70 acres. I've always liked the countryside but I didn't know much about it until my bloke started teaching me. Though, when we were kids, we used to get in the car on a Sunday and drive off to the country."

When her daughter, Maisie, was two, the child was diagnosed with leukaemia. "She was very ill, and she's only now at 10 been given the all-clear." She says the illness prevented them having more children.

"About the time we were thinking of more, she became ill and now I'm too old."

Walters got used to having to face the idea of death. "Children are a lot better about it. There were children we knew who died. I remember Maisie talking about dying, she was very matter-of-fact and said to me: `Aren't we supposed to come back after we die?' I said: `Yes, that's what they say' and she thought about this and then said: `I'd like to come back as a baby.' Isn't it great the things children say, they're much brighter than us. What happens?"

Life in the countryside is as normal as she wants it. "I love going to London, but it's great where we are. We've been there for 13 years. I know my trees and so on, but aren't sheep stupid?"

There is more to her life than acting. "I like just living. I was driven, but I'm not anymore. I love a good read and I am not ashamed to admit I like Joanna Trollope's books and yes, we do have an Aga." Her career has been based in England: she has yet to work in the US, which does not bother her. She has had a range of character roles, gritty Northerners and working-class women. Her parts tend to be real people. So is Britain a good place for an actor? She looks doubtful. "Well, it all depends on the writing. But the real problem is that people are really only interested in police and hospital TV drama. Theatre is not doing well. All the emphasis is on film and TV."

Who does she most admire? "Judi Dench. She can do anything. I would go anywhere to see her in anything." At the mention of another grand dame of British theatre, Walters considers this before deciding: "No, I'm not too crazy about her. Helen Mirren is very good as well, so's Fiona Shaw."

Dinner Ladies, a new comedy series by Victoria Wood, has just begun on television. Walters has a cameo part in it. "I wasn't supposed to be in it. She asked me did I want to and I said: `I'd love to, Vic, but I get so many things.' I suppose I was trying not to be greedy. Anyhow, she wrote this part of the mother. The character Victoria plays has this mad mother, she's bonkers and lives in a mobile home on the forecourt of a petrol station. The Victoria character is ashamed of her and has nothing to do with her. But she surfaces from time to time. She is quite bizarre, even unsavoury and dresses like a bag lady. She lives in a fantasy world, claims she had an affair with Frank Sinatra. And says things like `well, I said to Ole Blue Eyes'."

As she tells the story, Walters becomes the part. Standing in front of the open fire, she lifts each foot in turn before it: "Damn cold, isn't it?" she elaborates. Whatever the cliches about funny people being murderously solemn interviewees, Walters is disarmingly entertaining.

The monologue continues, fast, fluent and never forced; "She's called Petula Gordino and she speaks quite well, almost posh. But I don't know, she's probably up to no good. Maybe she did have an affair with Sinatra. You never know," she says, assuming the demeanour of a Home Counties matron, "with people who live on petrol station forecourts."