`The only secret kept in Washington in three years' was how President Clinton described the identity of the author of `Primary Colours'. How will he react, asks Cameron Docherty, when he sees the film, with its portrayal of a corrupt and scandalous presidential campaign?

If President Clinton was aggrieved at his on-screen inclusion in Contact, just wait till he sees Primary Colours.

The $65m feature is based on the best-selling roman a clef that portrays an ambitious Governor named Jack Stanton whose presidential campaign is rocked by sexual harassment scandals and accusations of draft dodging.

The movie, which opens next summer, is directed by acclaimed film maker Mike Nichols and stars John Travolta as Stanton, Emma Thompson as his loyal wife Susan, and Billy Bob Thornton as a campaign manager with a predilection for flashing.

The Random House novel, a wildly successful satire of the 1992 Clinton presidential campaign, riveted the entire nation, and not just for its risque content. The author added to the mystique surrounding the book by remaining anonymous, even to the publishers.

The quest to identify the source only intensified when President Clinton teased the White House press corps by saying it was "the only secret I've seen kept in Washington in three years."

The mystery began to unravel shortly after hand-written notes surfaced on an original manuscript obtained by the Washington Post. A document examiner matched the scribblings with the handwriting of Newsweek columnist Joe Klein, a viable suspect who always maintained his innocence.

"I'd rather Anonymous had remained mysterious," acknowledged Nichols, who hired the author as a consultant on the movie. "Now Klein will be tortured with questions about whether he took notes, whether certain conversations really took place - bringing the book back into the realm of non-fiction. I always regarded Primary Colours as a work of the imagination. The story has more power that way."

In 1995, the outline for Primary Colours was sent to a half-dozen film- makers handpicked by Klein, including Nichols, who was too busy working on The Birdcage to read it. None expressed interest, but the picture changed dramatically when Primary Colours took off. The mystery surrounding its anonymous writer helped to propel sales over one million copies, and the book became a fixture on the New York Times best-seller list for five months.

The opening bid for the film rights was $250,000, according to producer Irwin Winkler (Goodfellas), who had hoped to make the movie himself. Were it not for delays on the part of Klein, he recalled, the project would have sold for that amount.

"While waiting for an answer, sales increased and bidding became feverish," Winkler told the Los Angeles Times. "The town is hungry for original material - and there hasn't been a mainstream movie in that genre since Robert Redford and The Candidate in 1972."

Unable to get a studio to back him, yet convinced of its tremendous potential, Nichols took the risky - and highly unusual - step of buying the book rights himself for a reported $1.5m, beating rival bidders Columbia Pictures and Universal.

"Overt or covert, I had to have it so I could make the movie that was in my head," says the director, whose credits include Who's Afraid of Virginia Wolf, The Graduate, Working Girl and Regarding Henry. "The story deals with honour - a subject movies love. Whatever dirty deeds the candidate and his staff engaged in, they're reaching for the high ground."

Initially, Nichols approached two-time Academy Award winner Tom Hanks to play the charismatic governor, but with his strong ties to the Democratic Party and personal friendship with Clinton, Hanks felt it would conflict, and he backed out.

Other names bandied around for the role were Robert Redford and Kevin Costner, but Travolta, a powerful A-list star who has had a succession of hit movies - Phenomenon, Michael and Face/Off, was sought out and signed on for a reputed $20m.

Until now, all the actors - well, nearly all of them - have made a concerted effort to distance themselves from their real-life counterparts. "I absolutely didn't want to do an impersonation," insists Emma Thompson. "My character isn't Hillary; it's a composite of various people."

"I'm not imitating anyone," maintains Thornton, whose character in the book is a dead ringer for Democratic spin master James Carville. Indeed, the actor grew a close-cropped beard to differentiate himself from the clean-shaven Carville.

Adrian Lester, the young British actor whose pivotal role as narrator Henry Burton contains elements of Clinton confidant Ron Brown and adviser George Stephanopoulos, claims he's "just done a little bit of reading on Ron Brown."

But like a chief executive who throws caution to the wind and surprises his staff members by being more candid than they are, Travolta isn't the least bit reticent about his role's model. He's copied the President's hair colour, body language and a remarkably accurate honey-dipped Arkansas accent. "I'm really playing him," admits the actor, who studied hours of videotapes to prepare.

"It's false PR for me to do it any other way... unless there are some legal issues I don't know about." Washington pundits are wondering whether Hollywood would tone down the more salacious aspects of the novel. "We haven't changed any central events of the story in any way," claims Nichols. "But there are mysterious things being written about how we've handled things. I've read reports that we've taken the lesbian past of Mrs Stanton out of the story. Well, I've read the book five times, and we didn't take it out - it's simply not there in the first place."