Like a theatre curtain rising, the door opens to reveal one of British showbusiness's most familiar figures, sitting in an armchair in a pool of light, his pink complexion contrasting with the silver hair and beard that seem to glitter in the hesitant sunshine of a winter afternoon in Glasgow.

The status of national treasure and peer of the realm is an unlikely outcome for a boy who left school at 16, and lived in the shadow of a smarter, younger brother. At 77, Lord Attenborough is less Don Quixote than Sancho Panza, the nobleman's rustic servant, man of the people. He remains Dickie to his friends.

He has the air of a distracted uncle, forgetting to introduce me to his female companion, to whom he turns occasionally, calling her ''darling'' and what sounds like ''poppy''. Ordinarily, if someone calls a woman ''darling'', you might assume she was his wife, and Attenborough and his companion have the easy familiarity of a married couple - she wonders if her tea is all right and asks him to sniff it; he suggests she take his coffee.

Attenborough has been married to actress Sheila Sim for 56 years, long enough for even the most forgetful spouse to remember, but the mystery lady does not look like a mature version of the girl who got glue in her hair in the Powell and Pressburger classic A Canterbury Tale all those decades ago. For all the bonhomie, I do not feel I could simply say: ''Excuse me, but who is this poppy?''

Then Attenborough varies his routine and calls her Di. ''One day Di came flying into the office and said 'I've found the most marvellous story','' he says, and the penny drops. She is Diana Hawkins, who met Attenborough when she was a teenager in Rank's publicity department, became his personal assistant, and in recent times has been his production partner.

In real life, as in movies, Attenborough likes to tell his stories in flashback. ''Di lives in Twickenham and I live in Richmond, and Richmond Green is sort of between us, and on one end of Richmond Green is our joint doctor,'' he says, munching on a salmon sandwich. In the waiting room, Hawkins was leafing through an old Country Life, when she happened on a story about an American Indian, who wrote a best-selling book about the environment, came to Britain for a lecture tour, and met George VI and the future Queen Elizabeth.

But, after his death, the prototype environmentalist was exposed as a fraud, who came from Hastings and went to Canada in his teens. ''The important thing is it's the story of a man of extraordinary courage and conviction,'' Hawkins concluded. A little smile informs Attenborough's lips. ''I said 'He wasn't called Grey Owl, was he?' '' Attenborough adopts a feminine voice to yelp Hawkins's ''Yes!''

Cue another flashback, to 1937, and two boys in shorts queuing for hours outside a

hall in Leicester, with a mounting sense

of excitement. Attenborough was there, with his younger brother David, to see ''the

modern Hiawatha''.

''We sat in this huge hall, 3000 people,'' he says. ''Suddenly this figure comes out, standing about 10ft tall, because of his war bonnet; and of course the place went barmy with applause.''

Attenborough was struck by the drama. ''Dave, being somewhat brighter, actually listened to what he had to say. Dave, who since the Year Dot, was passionate about the wild and creatures and so on, retained a greater image of what we saw.'' The boys even got an autographed copy of Grey Owl's book. ''Dave's a bastard,'' says Attenborough, ''because he took the book . . . And, despite the fact I made the goddam movie, he's hanging on to it.''

Grey Owl died the following year, and the revelations that he was just another English boy playing at Indians, undermined not just his reputation, but his message, too. Many who paid to hear him felt betrayed, though the reaction in the Attenborough household was different. ''You didn't swear in my household, but I remember my mother saying; 'It doesn't matter a damn: all that matters is what he came to tell us','' says Attenborough.

Hawkins had the same reaction more than half a century later and, the director who

won an Oscar for Gandhi set out to make

a film about a very different Indian, with James Bond - Pierce Brosnan - in the title role of Grey Owl.

''Ma and Pa'' Attenborough shaped the social conscience that was to become a predominant force in their son's films. ''They were involved in an extraordinary number of conscious actions related to things they found admirable or deplorable,'' he says. Attenborough's father was a historian, who organised the evacuation of Jewish children from Germany.

''I left school at 16 - if that weren't the situation I might have gone on to university, I might have been able to write, I certainly might have gone into something academic or political.'' But it was David who won a scholarship to Cambridge University and became a distinguished naturalist. There is a third brother, John, whose passion was cars - he had a garage and now lives in anonymous retirement in Bournemouth.

Attenborough met Sheila Sim when they were students at Rada. ''When I was married Sheila was the star and I was an also-ran,'' he says. That is not entirely true - in his teens Attenborough co-starred with Noel Coward and John Mills in the war film In Which We Serve, but Sim gave up a glittering career to raise their three children. They now split their time between London and a remote farmhouse on Bute, where Attenborough works on scripts, and which serves as a holiday home for their children and seven grandchildren.

Asked the secret of such a long showbiz marriage, he says: ''Not spending too much time together.'' But he also feels some showbiz couples do not see enough of each other. He and Sim appeared together in several plays in the early years of their marriage, including The Mousetrap.

Attenborough sits as a Labour peer, but regards his his films as his most important contribution to social justice, singling out Cry Freedom, about the murdered South African activist Steve Biko. He has always found real people and stories more interesting than fiction.

''Gandhi, Steve Biko, Charlie Chaplin, Ernest Hemingway, etc are figures who are worth looking at,'' he says. ''If I can be paid for spending hours working on a personality and getting to know a personality, it's a gift from Heaven.'' I wonder if it is also a form of continuing education. ''That's what she says,'' and he nods towards Hawkins. But, in an unlikely echo of the Stranglers, he complains society has no more heroes any more.

It took him 20 years to get Gandhi made. Hawkins recalls the studios wanted Richard Burton in the lead, and they raised the money outwith the studio system. Grey Owl was also independently financed, but whereas Gandhi went on to Oscar glory, Grey Owl went straight to video in the US and appears in British cinemas more than two years after it was filmed.

One distributor came bounding out of a screening, pleading to be allowed to keep the print for the weekend, so he could show his wife and friends. ''He said 'But of course, it's no good for us . . . there are no special effects, no violence, and virtually no sex. How the hell could we sell it?' '' Attenborough sounds genuinely hurt and bewildered when he says: ''It's never happened to us before.''

Grey Owl is picturesque, epic, quietly uplifting, entertaining, and educational. It is also heart-felt, sentimental, and old-fashioned. Just like its maker.