AN HOUR before I'm due to meet Sue Townsend in the London offices of her publishers, I get a call. She would like to see me at her hotel instead, if it isn't too much trouble. Townsend must be feeling ill today.
In 2001, she was registered blind as a result of her diabetes. She also has Charcot's joint, a related illness that has weakened the bones in her legs and feet and means she has to use a wheelchair. Still, she continues to bash out the diaries of Adrian Mole, and has just published a ninth instalment, The Prostrate Years.
She began writing about her working-class anti-hero when she was 36 and he was 13. She was struggling on an estate in Leicester with three children and no money, he was struggling with teen angst, pimples and Thatcher government. In the 27 intervening years, neither has grown up all that much, she says later.
On the outside, though, everything has changed. When Townsend is wheeled into the hotel drawing room by her granddaughter, she looks exhausted, like the last thing she should be doing is an interview. She looks the part of the bestselling author – glamorous jacket, eyeshadow, patent ballet pumps, big professional smile – but none of this detracts from how pale and frail she seems under her armour.
"I'm a bit rough today," she says. "Oh, it's all right," she adds quickly when I start making sympathetic noises. "It rarely happens. I just wish it hadn't happened today. I haven't been able to eat for a few days. The thought of eating makes me gag actually."
Her son "very kindly" gave her a kidney and three months ago she had a transplant. It's made a huge difference, but the drugs she's taking are making her squiffy. Still, she gamely makes light of it. "It was great getting my own morphine. I could press the button any time. Eventually they had to wrestle it from my hands."
At times, though, Townsend becomes confused, checking what day it is, asking her granddaughter – to whom she dictated The Prostrate Years – to remind her of a character's name, and apologising because "my head keeps going". She keeps insisting that she's fine, just not at the moment. "The frustrations become bearable because they have to be. I think it's so ill-mannered to make everyone around you feel miserable. I can't bear a hypochondriac."
Last time round, in The Weapons Of Mass Destruction, Adrian was raging about Tony Blair's decision to go to war in Iraq. It was a darker, more splenetic instalment and Adrian seemed to be finally growing up, his mounting debt aside. The Prostrate Years is even darker as, in his 39th year, living back in Leicester in a converted piggery beside his parents, he learns he has prostate cancer. The backdrop this time is Gordon Brown's entry into Number 10, the credit crunch (though Adrian feels safe as he has moved his savings to an Icelandic account), and his first love Pandora, now a cynical MP who bought her sheepskin coat on expenses.
Why did Townsend give Adrian a life-threatening illness? "I wanted to do that to him," she says with a wicked laugh. "I suppose it's because I've had a lot of illness in my life. No-one ever writes about it in a comic way. We're frightened of it. People have only just started to say cancer out loud. In Leicester, they used to call it can-ker." She laughs and then gets the hiccups. "This book has a few dark shadows running through it." She corrects herself. "No, shadows can't run. They fall."
Writing has been cathartic since she started losing her sight. In The Weapons Of Mass Destruction, Townsend made Adrian's best friend Nigel blind and vented some of her anger and her next book, a novel, is provisionally titled The Woman Who Went To Bed For A Year. "I wanted to make somebody blind," she admits of the Mole diaries. "I thought I'd make it happen to nasty, acerbic Nigel, this foul-mouthed gay man, so there wouldn't be any of that tiptoeing around. You know, treating you like a tragic heroine." She isn't talking about Nigel.
The impact of losing her sight on her writing is fascinating. Dictating the books, she says, has made them better. "Certainly tighter. The rhythm of the sentences comes naturally because I'm speaking them aloud." Nowhere is this more evident than in the Mole diaries, where Townsend seems to inhabit Adrian more with each book. She feels like they're becoming closer and says "it would be like half of me had died" if she stopped. And now that she speaks his words out loud, she sees the world through his eyes even more. This is the first book she has regretted finishing. "Yes, it's funny isn't it? I channel him more."
In the past Townsend dictated to her husband of more than 30 years, Colin, but he's busy running pubs and his canoe business and she says the secret of a successful relationship is doing things separately anyway. He still reads to her though. The most painful part of losing her sight is not being able to read – she devoured books even when on the verge of giving birth – and, because her diabetes has affected the nerve endings in her hands and feet, she can't use Braille.
"Writing is getting harder," she says. "Like today, I couldn't write a damn thing. My brain actually hurts when I'm working." Somehow, though, I can't imagine her stopping. In a way it's Adrian's tragicomic voice that has helped see her through. "I think my parents thought I'd have a more glamorous life," she says. "A sort of Barbara Taylor Bradford life with furs and jewellery. A picture on the back of my novels, backlit, with a cigarette and extraordinary make-up." She laughs again. "I might do it just to please my mother before she dies." v
Adrian Mole, The Prostrate Years is out now, Penguin hardback, 18.99
• This article was first published in Scotland on Sunday on 08/11/09