Partner tells of unconvential life with literary giant JG Ballard

But in the last months of his life as he lay dying of cancer, the novelist finally moved in with Ms Walsh, swapping his suburban home in Shepperton for her flat above a boarded-up shop in Goldhawk Road in west London.

Today Ms Walsh told the Evening Standard of her devotion to Ballard, author of the bestseller Empire of the Sun, and how she cared for him in the weeks and months before his death yesterday at the age of 78.

She said: "By June he was no longer able to look after himself and moved in here permanently. The most important thing was he wanted to be here and I wanted him too. It was only the last few days that his illness accelerated rapidly and that was deeply distressing but I am glad to say he was comfortable for most of the time.

"It was the first time I had him under my roof. It was the greatest joy to me to be able to care for him by myself. Now I am absolutely bereft.

"I had always rather hoped that one day we would move in together but he he needed his solitude in Shepperton for writing and we settled into a pattern that we would see each other at weekends and midweek and go on holidays together. We always spoke every day on the phone, at least once.

"I would have loved us to have lived in a nice house with a nice garden and live the bourgeois dream. But Jimmy was amazingly unmaterialistic. That was one of the great and attractive things about him. The thought of going to an estate agent would really appal him."

In 1964, when his wife died suddenly of pneumonia, Ballard was left to bring up their three young children on his own, writing his novels and short stories at his home in Shepperton while they were at school.

A few years later, in the late Sixties, Ballard was introduced to Ms Walsh at the Ladbroke Grove home of science fiction author Michael Moorcock, one of his oldest friends.

Ms Walsh, now in her sixties, and editing a shipping news bulletin, was a few years younger than Ballard and had a daughter of her own from a failed marriage.

"It was a real coup de foudre," she recalled. "It was very exciting. I knew he had been set up to meet me but he didn't know. Mike [Moorcock] looked at both of us and thought we were suited. It was in the late Seventies that she and Ballard engaged in a "blazing row" that led to them splitting up.

"I nearly married two other people on the rebound," she said. "For as long as five years we were not in touch. Then out of the blue I rang him because I had seen a car going down the road that reminded me of his. He just said, I was waiting for you to ring' and from then on we got back together.

"It was just before he started seriously writing Empire of the Sun. We had moved from the normal kind of volatile relationship people have to becoming a sort of Darby and Joan.

"We were never short of things to say to each other and we were very happy in each other's company. I cannot imagine a world without him.

"A lot of writers would have been spoiled by Empire of the Sun but he never was. You see one or two writers who are filled with self-importance. Jimmy never ever felt that. He never exploited his name. Publishers loved him because he was such a nice person to deal with."

Ballard was diagnosed with advanced prostate cancer in 2006 but fought the illness to publish his critically acclaimed autobiography, Miracles of Life: Shanghai to Shepperton, last year.

Now Ms Walsh must try to come to terms with his death. "It's just awful," she said. "I found it very hard to let him go yesterday. I lay next to him and stroked his head and just enjoyed the feeling of his face under my hand."