She describes herself as the 'supply teacher of comedy', the one who drifted through jobs while her peers rose to great heights, but Helen Lederer's peripatetic talents are now finally being realised.

For the first time in her career she's being nominated for an award - a literary one at that. Her debut novel, Losing It, has been shortlisted for the Bollinger Everyman Wodehouse Prize for comic fiction, alongside books by the likes of Caitlin Moran, Irvine Welsh and Alexander McCall Smith

"It's extraordinary really, because I don't get nominated for things," she explains. "My chances of winning are nil, but to have the word 'nominee' is enough.

"The top people have been honoured with all honours. They have to build second houses to put all the prizes in that they've been given. Oh, there was a Sony Award which I did once get for In One Ear (a late-night alternative comedy radio sketch show), but I did that at a time when nobody archived it, so I don't think there's even a photograph of that."

Lederer, 60, cut her teeth in stand-up at the Comedy Store in the Eighties, alongside French & Saunders, Rik Mayall and Harry Enfield. She went on to guest-star in an array of TV and radio shows, as well as playing ditzy magazine editor Catriona in Absolutely Fabulous.

It's impossible to pigeonhole her though, because she's also a prolific comedy writer, has starred in fringe and major theatre productions, including Educating Rita and Calendar Girls, and recently returned for a stint on Hollyoaks playing an eccentric midwife.

"If there had been a sitcom, if I'd have been June Whitfield, that would have been great. I'm waiting for the part," she quips. "It's great that there are more women out there creating their own work and I'm right behind it."

Losing It charts the misfortunes of Millie, a divorced, middle-aged magazine agony aunt who is offered the chance to front a new diet pill to earn enough to clear her debts, but has to lose three stone to claim her fee.

Lederer, who describes the novel as 'mid-lit', says it's not autobiographical, but her experience of weight problems, money issues, divorce and bringing up a daughter has undoubtedly influenced the writing.

"I would never write an autobiography - I've blocked most of it out anyway - but in terms of trying to lose weight, I've had colonics, I've had amphetamines, I've done most things. It's a novel on other levels. There's a jeopardy because she needs the money, but my aim was for people to read it on the tube and laugh out loud."

She admits she's had a lifelong battle with her weight, and still diets.

"Oh, it's forever! I'm in my own body programme. In a funny way, I've made it my friend. What's nice is to have hope and possibility, even if it's entirely fictional, so the thought that I might lose weight keeps me going.

"Because - and here come the excuses - I don't have the discipline. Some nights I drink four or five vodkas, some nights I'm in bed in my pyjamas at eight, there's no routine and it's very difficult, particularly at this age, to say, 'I'm going on a regime for the rest of my life and I'll hardly eat anything and I will be thinner and my life will be better'."

Is she obsessed with food?

"I really don't know why I'm overweight. I don't know if I sleepwalk into that fridge. I certainly like being near to my fridge. I don't eat that much. I have a low metabolism - doesn't every fat person say that? I don't exercise. I find being out of breath horrible.

"Nowadays, you see people running and cycling. I should do that. There are so many things I should do, and I accept that, but at the moment I'm not a size 20 - and there's nothing wrong with being a size 20 - but I'm average, because they say the average is size 16 and I'm probably that."

She's based the relationship between Millie and her daughter in the book on her own relationship with daughter Hannah, 24 (from her first marriage; Lederer is now married to second husband Chris Browne, a GP).

She has recently found herself on the literary festival circuit. "I don't know if there's any money in it, but you do get to have nice sandwiches in a green room and you meet very jolly people. It's a departure but I'm embracing it."

She has not, up until now, received the accolades or fame that some of her Comedy Store peers enjoy, but isn't jealous.

"I've had moments when I wanted more, when it just wasn't my time. I gave stand-up a year and I did it for five years. Each time, I'd think, 'I'll just give it another year', because it's kind of an addiction."

There was some jostling for position in those early days, with such a melting pot of talent.

"I was after French & Saunders, who were already ring-fenced for their own enhancement, but there wasn't a space. Women are complicated and competitive, particularly in those days when comedy was very difficult to define. It was quite a toxic environment to be in. I was very naive."

She continues: "I don't feel miffed, because what's great about this middle-aged phase is an acceptance that my career has gone in so many different ways, and that was right for me. I had some near misses, but what matters is I'm here now, I've written this book and I've kept working throughout. It's OK to do it in a more bespoke, minority, less famous manner."

She keeps in touch with Dawn French, with whom she worked on the Eighties series Happy Families. French is godmother to her daughter, Hannah.

"Getting to know someone while you're working with them is the best way, and we laughed and laughed, but we are not in and out of each other's houses all the time."

More recently, her foray into reality TV, notably celebrity diving competition Splash!, was not so enjoyable, she admits.

"Splash! was a one-off. I try not to think about that, but on the other hand, I did the bloomin' thing! I could have walked the other way off the board and down the steps."

She also presented Big Brother's Bit On The Side, but doesn't feel that being a housemate on Celebrity Big Brother would be for her.

"There's a worry that I'd go a bit loopy, so I'm not quite sure if I'd be a safe bet. I'm not sure I'd want to expose my shortcomings, of which there are many, in front of the nation. I've already exposed my body, which was hard enough."

Having been a judge for various literary awards, she's now in the process of launching her own award, Comedy Women In Print (CWIP, get it?), for which there is already a website (www.comedywomeninprint.co.uk).

In the next few weeks, Lederer will settle down at home in London to write her next novel, another 'mid-lit' tale.

"To just accept one's lot is such a gift, having beavered away for 30 years. It's nice to be realistic."

:: The Bollinger Everyman Wodehouse Prize winner will be announced during the Hay Festival, which runs from May 21-31 (www.hayfestival.com)

:: Losing It by Helen Lederer is published by Pan, priced £7.99. Available now