Former President Valery Giscard d'Estaing dashed speculation on Wednesday that he once had an affair with Lady Diana, saying his novel about a romance between a French leader and a British princess was pure fiction.

Giscard, who was president of France from 1974-1981, set tongues wagging because the heroine of his love story, Princess Patricia of Cardiff, was clearly based on Diana.

The patrician elder statesman moved swiftly to deflate the rumors, saying that although Diana was the inspiration behind The Princess and the President, his book was not a true story.

I invented the facts, but not the places or the interiors, Giscard told Le Point in an interview released before the magazine's publication on Thursday.

It is a novel where Princess Diana is the main character. I tried to bring her back to life as she was when we met, he said, scoffing at gossip he might be reliving a past romance.

Let's not exaggerate things. I knew her a bit in a climate of trust, he said. However, he revealed that Diana herself had given him the idea for the book.

We were talking about love stories between the leaders of major countries and she said to me 'why don't you write a book about it?' the former president said.

In the summer of 1997, the two met again and Diana asked him how the novel was coming along. Six weeks later, she met a tragic death (in a Paris car crash). I thought it was a promise that I had to keep, Giscard said.

The book starts with the inscription: Promise kept.

Giscard, previously famous for penning the European Union Constitution that was killed off at birth by a French referendum in 2005, complained that many in France saw little use for former presidents.

They only have the right to publish memoirs that no one reads. I have never accepted this and as time passes I feel increasingly free, he told Le Point.

His novel is due to be published next month, shortly before his long-time political foe, Jacques Chirac -- also a former French president -- publishes his first volume of memoirs.