Jilly Cooper is exhausted. The night before our interview was the launch party for her new blockbusting novel Jump! and as usual she was in sparkling form, greeting old friends with her customary exuberance, posing for photographs and at the same time keeping a weather eye on her husband Leo, who has Parkinsons and had made a special effort to be there. "He's so wonderful and has been so brave. I was so pleased he was able to be there. He's in a wheelchair but he had a lovely time and all the women were bending down to speak to him and make a fuss of him," she says as she settles into a sofa at London's Royal Houseguards Hotel.
She has lost weight, thanks to a dairy-free diet that is helping to bring down her cholesterol level, and she looks nowhere near her 73 years, but a slight stroke just six weeks ago took her by surprise and she's lost a little of the bounce that earned her the nickname Jolly Sooper in the 1970s. She still has trouble with her wrist, having broken it slipping on the stairs, and she has just started a projected two-year marathon in the dentist's chair, having several implants. She has already had three wisdom teeth taken out.
"I was sitting on Leo's bed chatting away and I just suddenly keeled over. It was one of those little TIAs or transient ischaemic attacks. They rushed me off to the doctor and next thing I was in hospital. I'm perfectly fine now," she says showing off a 10cm curved scar on her neck where an artery was "scraped" by the surgeon. The past four years of toiling over her latest romp through the stables and racecourses of her imaginary Larkshire have been draining and the worry of Leo's illness has clearly taken its toll. Her gap-toothed smile is never far away but her face clouds over as she talks about it.
"Everyone is asking me why I keep on writing and I think it's a bit sad that it always comes out that I write to pay the bills. That is not entirely true. I actually love the writing process. But the fact is that Leo isn't very well and his round-the-clock care bills are horrific. It's probably about £100,000 a year to pay for full-time carers, and that's one reason why I've got to go on writing pretty hard. We are lucky we have heavenly carers. I've got to keep on writing but it's not a problem because I love doing it," she says.
She writes in an office in the attic of her Cotswold manor house, The Chantry, which has had stair lifts and ramps fitted to accommodate Leo. Each novel is laboriously typed on the ancient portable typewriter she calls Monica. Part of it was typed on the back of an old manuscript of her novel Riders, Cooper's small, if slightly eccentric, contribution to recycling. "Every time I turned over and read a bit of Riders I kept thinking it was so much better than the one I was currently writing. I was so worried that this one wasn't very good and at one point thought I would just pay the advance money back to the publishers."
Another reason for the longevity of Jump!'s gestation was her almost permanent state of tiredness. "I don't get much sleep at the moment. Leo wakes quite a lot in the night quite often and needs something," she says and the distressed look flashes across her face again. "He keeps telling me I must get a deaf aid but I don't think I'm deaf, it's just his voice is getting quieter and quieter and I keep having to ask him to repeat things. We still have jolly times." He is funny and "he's very good in the mornings", she adds.
Cooper speaks like she writes and both her real and imaginary worlds are filled with "ravishing" women, "wildly handsome and dashing" men and extravagant and colourful descriptions. Some of her favourite characters, including Rupert Campbell-Black and Billy Lloyd-Foxe, appear in Jump!, along with its central heroine, Etta Bancroft, a woman in her mid-sixties whose bullying husband dies and whose selfish, children, Martin and Carrie, drag her from her family home to live in their village.
The fictitious Willowwood is filled with a splendid array of characters, tycoons, trainers, stablegirls, actresses, an ambassador, a crotchety old gardener and a lovelorn teacher. The goings on of the horsey set are fodder for Cooper's fertile imagination although sometimes truth is even more astonishing than fiction. "We had a launch party in the country and I invited a lovely trainer called Kim Bailey and his lovely second wife Cookie. They had just arrived when another trainer, Charlie Mann, walked in with Kim's first wife Tracey Bailey, so I had to rush round telling them that the other half was there. Nothing is exaggerated at all in my books. All trainers have lovely young girls around them, and if they're not people invent them."
Another little vignette in the book sees village women taking shepherd's pies and casseroles round to the home of a rather attractive man whose wife is away. "That sort of thing definitely happens," says Cooper. One of her neighbours is the actress Elizabeth Hurley, who was invited to a summer lunch party Cooper held to thank all the racing people who had helped her research. "I told all the men she was coming and they were terribly excited and coming from the North Pole to see her. Then I got a phone call from her secretary to say that she couldn't come and they were all desperately disappointed.
"A few days later a parcel arrived containing a beautiful leopardskin jewelled kaftan. It's heavenly and I wore it to the launch party which we held in the Household Cavalry Museum," she says with her usual breathless delivery. "It was packed with unrough trade, lovely aristocratic boys with long eyelashes holding their caps off. There were gorgeous cavalry officers with huge black chargers outside on duty. It was a very nice party but it was very tight on numbers so I said only people with jockeys' weight can come."
She clearly had fun researching the 739-page novel, and typically joined a syndicate called Thoroughbred Ladies so that she could get a real hands-on feel for the racing fraternity. "The research was heaven, I went to Cheltenham because that's very close and of course to the Grand National where there were some marvellous parties. I had a brilliant time although I never find the actual writing fun because I'm so slow. It's so exciting to be part of a syndicate. When a horse wins everybody sobs and screams and hugs him and when he loses it's awful," she says.
Her research took her to Darley Stud at Newmarket, owned by Sheikh Mohammed bin Rashid, Vice President and Prime Minister of the UAE and Ruler of Dubai. "It was awesome, the most beautiful place in the world and there was not a leaf or a blade of grass out of place. I saw these wonderful huge beautiful stallions that won Derbys out to grass and when they die they put a plaque on the graves saying who they were and how much money they earned."
The BBC gave her permission to shadow the commentator Richard Pitman at the Grand National. "I was incredibly lucky with Richard and was allowed to follow him around beforehand and during the day. They had a planning meeting attended by 200 people just to organise the filming." Pitman has a walk-on part in the novel and Cooper says several of her real-life male friends were the models for Rupert Campbell-Black, including Andrew Parker Bowles and Rupert Lycett Green. "They are thrilled and they all claim it's them and go around saying it's them, and it is a bit of all of them. Years ago I was having lunch with the publisher George Weidenfeld, long before I went to Gloucestershire, and told him I was writing a book about an incredibly nasty, but very beautiful man just like the man sitting over there. And he said, 'Oh that's David Somerset' who became the Duke of Beaufort, so he was the prototype."
Etta, she says firmly, is not herself, although many people have remarked on the similarities. Her heroine is mad about animals and has the same soft, fluffy quality as Cooper. In the author's case, though, it masks a steely determination, sharp intelligence and self-deprecating sense of humour that has always been so disarming. "I have much fatter ankles than Etta and she's much nicer than me," she says as if to prove the point. "And Leo definitely isn't Etta's husband Sampson, who is such a pig.
"I love the story about Sampson looking for his heated pad and finding it in the dog basket, and he was furious. Leo's not at all like that, he would love the dog to have a heated pad. There's lots of me in Etta, she's mad about animals and has a terrible wetness about her," says Cooper who once found a wild cat and took a year and a half to train it to come indoors. She named it Feral. She also has a lovely old rescued greyhound, Feather, which she insists makes a wonderful pet.
She agrees that Etta's family are dreadful. The Racing Post's reviewer described them as "the most repulsive characters in literature. King Lear didn't know his luck." Cooper worries that she might have got that wrong. How could someone as sweet-natured as Etta have such horrible offspring? "But they both clearly had their father's genes." She does know people who remind her of Martin and Carrie and their other halves. "There's a sort of prototype." There's a similar character in Polo who was terribly up himself, venal beyond belief, who was trying to get people to sign up to his new charity at the father's funeral."
Jump! is Cooper's 16th novel and like most of the others has shot straight to the top of the UK book lists. Her first big novel, Riders, published in 1985 did the same, as did Rivals, published in 1988. Polo, which came out in 1991, was the highest-selling hardback novel of the year. The Man Who Made Husbands Jealous sold well over one million copies and was made into a television mini-series, as was Riders. Appassionata and Score! were also runaway best sellers.
Her first book, How to Stay Married, was written in 1969 and since then she has written or helped to compile 39 others, including the 16 novels. In 1970 she wrote a TV series about four girls in a flat entitled It's Awfully Bad For Your Eyes Darling, in which her friend Joanna Lumley played a starring role. Her best-known non-fiction book was Class, a subject that clearly fascinates her and peppers her fiction. The class system is alive and thriving in her fictional counties of Rutshire and Larkshire and indeed in her home county of Gloucestershire. "People are very proud of it being the most beautiful county in the world and at one point having three members of the royal family living here. Princess Michael has gone now but we still have Prince Charles and Princess Anne, who is marvellous."
Despite her success Cooper, who first came to fame writing columns about her life as an urban housewife for The Sunday Times, is a worrier and says she's hopeless with money. "I don't mind earning it and spending it, but I don't want to know what's in my bank balance every single minute." Although she has always had a delightful air of daffiness about her, Cooper, who was appointed OBE for services to literature in 2004, is a resolute coper, a quality that stood her in good stead when early in her marriage she suffered an ectopic pregnancy that left her unable to have children. She and Leo adopted Felix, now 42, and Emily, now 39, and have four grandchildren, Jago, Lysander, Acer and Scarlett, plus one on the way.
They will have been married for 50 years in October next year and, like many long marriages, theirs has suffered a major trauma, in their case when Leo's mistress of several years decided to go public. Leo's affair was "crucifying" and Cooper admits they went to the counselling service Relate to try to patch up their marriage. They clearly adore each other though, and Cooper's anxiety about her publisher husband's health frequently creeps into her conversation. As always, she is open and forthcoming about her troubles in an endearing way.
"I think it made me much nicer. I think I was probably very smug. There's a wonderful quote from TS Elliot which says you will survive humiliation and that's an experience of incalculable value and I was humiliated, babbling on to the press about my wonderful marriage. It was horrid. We do have a lovely marriage and I'm jolly lucky. Dear Leo, being married to a famous wife, it's not a doddle." Throughout her marital troubles and Leo's illness, Cooper has been sustained by the friendship and support of people in her village. She will often come home to find a pot of home-made jam on the kitchen table or a porch filled with flowers left by an old friend.
"People in the village have been wonderfully supportive and they're not insulted if you don't come to dinner. Everyone is so sweet and kind." She has already mapped out her next book which opens around the time of Rupert Campbell-Black's 60th birthday. "You can imagine the traumas he's going through. Richard Branson has just turned 60 so I shall ring him up and ask him about it. Poor Taggie, Rupert's wife, is getting a surprise party organised and can't decide whether it should be at the Melbourne Cup or the Gold Cup in Dubai."
Clearly she can't wait to be back in her world of handsome rakes, ravishing women and beautiful animals. "It's like starting a new adventure and entering a new world. I've written a book that I thought was a dead duck, I've had a lovely party and Leo's all right at the moment. I'm very happy."