The secret life of Gregor Fisher: the star of NTS's new show Yer Granny reveals some surprising facts about his past ... and Rab C Nesbitt's future

Fisher admits he is "old school", the type of actor (like his former mentor Rikki Fulton) brought up to believe journalists are a necessary evil. And that's frustrating because not only is he likeable, he's sharper than Nesbitt termagant Ella Cotter's nails, with plenty he could say about life's slings and arrows. Given up for adoption aged three, Fisher left school at 15 to literally shovel s*** in a chicken farm, later working in a toilet factory before finally finding his personal rescue centre when he realised he could act and was accepted by Glasgow's RSAMD. Since then he's won plaudits for his theatre work, his film appearances alongside the likes of Al Pacino (Merchant Of Venice) and John Hurt (Nineteen Eighty-Four), and of course, for his role as the eponymous street philosopher in Rab C Nesbitt, which evolved from a Naked Video sketch to BBC2 sitcom in 1988, featuring wife Mary'doll and chums Jamesie and Ella Cotter.

So of course he has tales to tell. And questions to answer. Why, for example, has the 61-year-old turned down work more often than Jamesie Cotter, with great theatre offers such as Art (the West End hit which featured Albert Finney and Tom Courtenay) being passed up? On a more prosaic level, why is he forever moving around (he currently lives in France), changing and rebuilding houses (and lives)? And what about Rab C Nesbitt? There's been talk Fisher would love to take Rab and Mary Doll back onto the stage. Is this about a love of live performance or is it because the bank account statement is turning reddish, having been drained by three kids going on to uni?

So many questions. Yet, even Shanks, the Royally-approved toilet maker he once worked for in Barrhead near his home town of Neilston, would struggle to flush out a good story. But then an odd thing happens. When we meet in Glasgow's west end to chat about Fisher's appearance in new National Theatre of Scotland production, Yer Granny, the Scots translation of the Argentine play La Nona, Fisher as usual offers his time-honoured deflector nonsense about him being "no' interesting blah blah". But then he opens up in a way he never has before.

It begins with a congratulatory comment about my biography of Mrs Brown creator Brendan O'Carroll, and segues into the actor revealing he's been working on his own life story. Are you serious Gregor? You're the man who wouldn't confirm you had kippers for tea last night in case it proved contentious.

"Ah, well, I've been thinking for a while about it, and was prompted by a friend," he reveals, sotto voce, in spite of the fact there's no-one around. "So it's coming out this year." And what will it cover? His own backstory? Well, yes. Fisher reveals he's been researching his family tree and discovered branches he never imagined existed.

"My early life was a mystery to me. There have been bits of my life revealed over the years, but not much more than the fact I was an adopted boy. However, I've discovered recently my adoption itself is something of a mystery, a bit of a ball of wool that's become entangled."

Trees. Branches. Balls of wool. Did he get to the end of the wool? Fisher is about to answer but checks himself, aware of the publisher devil on his shoulder.

"I got to the end of the ball of wool but there are still unanswered questions." He pauses and obfuscates: "It's like you. Do you know everything about your parentage?" No, Gregor, but I do know who my parents are. Do you?

"Ah, well. I've discovered some interesting details along the way." He offers a taster. Fisher never knew his biological mother, who died of heart failure when he was three, nor his real father. He was adopted by the Fishers and then adopted again by Cis and John Leckie. Or so he thought. "I wasn't adopted twice," he says. "I was adopted once and then handed over. And recently I discovered my biological father, or rather the man whom I thought was my father, was not my real father at all. It was simply assumed."

He adds, with a sigh: "People I grew up with would look at this man and then me, and say, 'You cannae deny that yin'. I remember when I went to drama school and realised I walked with a turned-in foot, as did this particular man. I thought, 'There's no question he's my father.' But it was all wrong, even though we looked similar."

So what actually happened? "It's an incredible story. My father, I've discovered, was a much, much older man. He was in his 60s when I was born and when my mother died, social services took us [he had sisters] away."

Gregor was given up for adoption to the Fishers. But then they gave the young boy away to another couple, the Leckies, who would bring him up. Why? "Because of various events and accidents and death," he says, rather cryptically. "I'm guessing the mother just couldn't cope." But he wasn't re-adopted by the Leckies.

"I don't know why this was the case. And because I was so young I didn't know this woman who was looking after me wasn't my mother. She was in her 50s at the time, and it was extremely unlikely she could have given birth to me, but of course this didn't occur to a three year-old."

This was the early 1950s, a very different time when children could be handed over to willing couples without the involvement of government agencies.

"It certainly was," he says, almost in disbelief at the protocol change. "People will think I'm making this up."

Why did the Leckies not drop the Fisher surname? "That's a very good question," he says, lifting his eyebrows.

Fisher won't reveal the name of his natural father - he's saving that for the book - but now that he knows his lineage, is he better placed to understand his place in the natural universe? "No," he says, with a tight smile and then adds: "Look, you have to consider that for years I was thinking, 'Who cares, why rake up the past, blah blah'. But as you get older you want to know, I suppose." He must have gained something from the knowing? "Quite a lot, but then again I gain a lot living every day."

Come on, Gregor. Be less obtuse. "OK, well you do gain from knowing your family," he concedes, grinning. "For example, I learned that my family were as working-class as could be and came from Coatbridge. I learned both my grandfather, then in his 30s, and my father, both fought in the First World War, in the same regiment.

"And while nobody outside of my circle knows that I play piano, it turns out my grandfather was a church organist. It's these things that let you feel that connection. Little bits of information add up to something, although I'm not quite sure what something is. But I've seen pictures now of my father and I can see the resemblance. It's really very weird to see."

He adds, breaking into a laugh: "My grandfather had a concert party [a group who performed variety shows]. So I guess performance really is in the DNA."

Fisher grew up with "hunners of sisters" - biological, adopted, half-sisters - and over the years he has said he'd often wished he had a brother. Did the ball of wool reveal a male sibling? He wrestles for a moment before answering. "Yes, and he was one of your kind." A journalist? "Yes, and he worked for the BBC. And years ago, in the BBC canteen in Edinburgh, I sat a few feet away from him, never knowing he was my brother." Is he still alive? "I have to keep something for the book," he says, grinning.

Does he feel bitter he never grew up in the standard family? "I thought I was in a standard family," he says, adamantly. "It's all you know. I don't feel I was dumped at all. And my mother (Cis, who brought him up) was certainly the centre of my universe."

Fisher created a new universe when he met actress wife Vicky Burton on stage in A Midsummer Night's Dream where he revealed his Bottom. The couple have three grown-up children. "She's been fine about this adventure of discovery," he says, pre-empting the question. "Vicky takes things in her stride."

How far does he go by way of personal revelation in his memoir? Past loves? Fall-outs? Seems he won't kiss and tell. "There are bits of my showbiz life en passant, but that's about it. I think that whole side of people's lives, their dalliances or whatever, should always be private." He adds, with a wry grin: "Everybody could put in stories about their love life, of being dumped or whatever, but it's all b*****ks. Who cares?"

The public, perhaps - who can empathise, take comfort from the fact actors bleed like rest of us. "In my day, you didn't talk about things like that. I'm only prepared to talk on certain areas."

Let's talk about career, Gregor. For years now you've resisted the stage like a kid resists cabbage. You've had occasional reprises in the likes of the musical Chitty Chitty Bang Bang, but turned down West End shows most actors would sacrifice their first-born for. Yet, here you are in La Nona, and later in the year you're going back to panto at Glasgow's King's Theatre, playing the Woodcutter in Snow White. Is this because Hollywood has stopped calling, and Nesbitt is stored in the freezer, waiting to be thawed out?

"As far as the NTS play is concerned, it's not about the money," he says. "The National Theatre of Scotland only pay enough to cover expenses ... two or three quid. But the truth is it's a really interesting play. I had seen it years before on television (1991) with Les Dawson playing the lead and it mystified me. Then when it landed on my desk I was intrigued, read Douglas Maxwell's interpretation and thought I'd really like to be part of it."

The part of La Nona, the grandmother, represents a real challenge. The play centres around a Scots/Italian chip shop family, whose granny eats them out of house and home so they have to turn all sorts of tricks to sate her. What is she? A semi-grotesque? A metaphor for advancing consumerism? A health warning? "Or the Argentine junta. Maybe she's the manifestation of Death? Maybe she's everybody's dilemma they're going through at this moment.

"This is a play that works on different levels," he adds. "It may not be for everyone, folk may get up and leave, but I don't think so. It's clever and it's very funny."

Dragging up holds no concerns; Fisher has worn frocks in Nesbitt, ITV comedy series The Baldy Man and 1980s sketch show Naked Video. "And this person is more of a monster than a female. So normal rules don't apply."

He doesn't want to see Les Dawson's performance. "I want to see what we can create here," he maintains. "But I'm still thinking, 'Oh my Lord!'" Yet, at the age of 61, he embraces the risk? "My son Jamie recited a quote to me recently: 'You should always do work that frightens you.' And I said to him: 'Who said that?'And he said: 'You did, Dad.'"

Yet, you could have been frightened delightfully in the West End? "I was lazy," he admits after a scratch of the brown, grey-speckled head. "That's my natural state. I don't need much of an excuse to do what I want to do. I can get real pleasure from fiddling about in the garden."

Laziness has perhaps been a defining feature in Fisher's make-up. It explains why he never passed his 11-plus and never made it to Paisley Grammar. It explains why he left Barrhead High with a single O Level in art and embroidery. Indeed, he never scratched and clawed his way into acting at all; his "epiphany" came about at school after one teacher, Mr Ball, threw a copy of the Mikado his way and commanded: "Learn that, Fisher. You're playing that part."

And he learned it, and loved performing it. When he appeared in a Noel Coward play he loved that too. And when he applied for RSAMD and was accepted he felt he had found his world. Over the years, he continually highlighted his talent with the likes of Borderline Theatre Company. But then he was able to walk away with a Nesbitt or a Para Handy or an Oliver Twist pay cheque trousered. What about needing the applause as most actors do?

"I've never been short of attention in my career," he says with a shrug. (Nor has he ever sought it.) "For me it's about the work."

The work? Ah. Returning to panto this year in Snow White in Glasgow as the Woodcutter - is this about an inner need to flash your big chopper? "They are paying me a little more than the NTS," he laughs. "And I get to appear with my old mucker, Juliet Cadzow (as the Wicked Queen). That will be a real laugh."

And Rab? What's the news? "You will know more than me," he says referring to my friendship with series writer Ian Pattison. Well, the story so far is that while the TV show is in abeyance, a theatre producer was interested but pulled back. If a new producer comes on board, and all the team agree terms, who knows?

"We'll see," says Fisher. "Next year is the 30th anniversary so if anything were to happen that would be the time."

It seems Fisher would like it to happen. He's keen to work and enjoying life more. He's even treating me as far less than evil (could that be because the ball of wool is now untangled?). But there's a final question. Over the years, Fisher and family have moved around more times than Rab C has signed on, from Ayrshire to Lincolnshire to the Borders. Right now he lives in the middle of France. Is this peripatetic life a metaphor for an inner searching?

"That's a question Vicky and me have asked ourselves many times," he says with a wide smile. "We're not sure, but it may be connected. She was the daughter of actors, always moving around, and I did quite a bit of moving as a kid as well. We did stay put for a while [in Dunlop], when the kids were young, but we like to go where the mood takes us." He adds: "Even though we set up home in France, we found we knew people in the area. Iain Glenn (whom he starred alongside in the BBC's Kidnapped) lives 10 minutes away and we are friends with a theatre couple we've worked with over the years who live up the road."

So is he happier these days? "Life keeps on going," he says. "It's demanding. People get ill. They die. You never know. You just try and enjoy it."

I'll take that as a 'yes'. And the book is good news. Fisher has indeed lots to say. It's just taken him a long time to say it.

Gregor Fisher stars in the National Of Theatre Of Scotland production, Yer Granny, which tours to The Beacon, Greenock; The King's Theatre, Glasgow; The King's Theatre, Edinburgh; Eden Court Theatre, Inverness; Lyric Theatre, Belfast; and Dundee Rep Theatre from May 19 to July 4

For further information and box office details visit www.nationaltheatrescotland.com