It is a tale of two bestselling books about 17th century Dutch painters which were both adapted into films. One was a joy. The other a “complete nightmare from start to finish” which ended in flames, along with Harvey Weinstein.

The writers Tracy Chevalier and Deborah Moggach told an audience at Hay festival of their hugely different experiences adapting their novels Girl With a Pearl Earring and Tulip Fever.

The hugely successful novels were both published 20 years ago and quickly optioned to be made into films.

Chevalier said they made a bet with each other on whose film would be made first, with the winner taking the other to the Ivy restaurant in London. “We had a lovely lunch together which I paid for,” said Chevalier. “The two experiences could not have been more different. It was a happy experience … It was all really straightforward and it didn’t take very long.”

Chevalier’s novel Girl With a Pearl Earring became a widely acclaimed film starring Colin Firth and a teenage Scarlett Johansson.

Facebook Twitter Pinterest Tulip Fever (2017). Photograph: Alex Bailey/Allstar

Moggach’s Tulip Fever, on the other hand, is a cautionary tale of how not to adapt a book. It involved at some point or another the author’s milkman, the screenwriters Lee Hall, Christopher Hampton and Moira Buffini, Steven Spielberg, Gordon Brown and Weinstein.

“Mine was a complete nightmare from start to finish … a ghastly disaster,” said Moggach.

Her book was optioned by Spielberg and she recalled flying off to Hollywood on Virgin upper class.

She told her milkman, Ron, of her Hollywood trip, idly promising him a role as an extra. When she returned from LA there were local paper headlines: “Milkman to star in Steven Spielberg film.” Then the national press started calling.

There was a saga over screenwriters. “It was me, they bumped me off,” said Moggach. “It was Lee Hall, bumped him off, Moira Buffini, bumped her off, Christopher Hampton, bumped him off, Tom Stoppard, he sort of vaguely did it in the end with all these other ones.

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“They lost track of what the film was supposed to be about. They had endless meetings, they were second-guessing Spielberg. There was no integrity to it. And the thing was, the book was like a film, they didn’t have to do anything really.”

In 2004, the $48m film was about to be made, starring Jim Broadbent, Keira Knightley and Jude Law, and involving hundreds of cast and crew. But Brown, who was then the UK chancellor, closed a tax credit loophole for films. “It was destroyed. All those people lost their jobs.”

A second attempt emerged. “Our saviour rode out of the sunset to rescue us on his white charger,” said Moggach. “Our saviour happened to be Harvey Weinstein. If you think it can’t get any worse, it did. He did actually make the film but everything went wrong.”

On paper, it looked like a great opportunity, with a starry cast that included Judi Dench, Christoph Waltz, Alicia Vikander and Cara Delevingne. Moggach was an extra – an old crone smoking a clay pipe and drinking a tankard of beer.

She said: “It was a complete nightmare because he [Weinstein] kept on interfering with it, he was very, very bossy.”

Despite everything, it was not too bad a film, she added. But “when it was just about to be released, he kept pulling it from the cinemas because he kept on fiddling with it because he’s a bully. Then just as it was about to be released … the whole sex scandal blows up.”

Moggach told Hay how she hired a cinema screen because she was convinced no-one would ever see the finished film.

There was lots of wine, 120 friends, but no big stars although there was a fellow extra from the film. “His part was cut,” said Moggach wistfully. “It was rather a nice occasion in a way.”

Her experience could not have been more different to Chevalier’s. “It says something to the generosity of my spirit that I still love Tracy.”

Moggach’s novel These Foolish Things was also made into a film, The Best Exotic Marigold Hotel. It was adapted by another writer, something the author does not generally like.

“It’s very like being away from your house and someone rifling through your knicker drawer … if it’s Tom Stoppard it’s not so bad,” she said.