By Edith Honan

NEW YORK (Reuters) - The antagonist in Bridget Siegel's debut novel, "Domestic Affairs," is a charismatic Southern politician who has an affair with a staffer while running in the Democratic primary for president.

But despite obvious parallels to the political soap opera that surrounded a real-life presidential aspirant, former U.S. Senator John Edwards, Siegel - a Democratic fundraiser turned novelist - insists the book is pure fiction.

"All the characters are composites of people I met over the years," said Siegel, who worked on the failed 2004 Democratic campaign when Edwards was on the vice presidential ticket. Still, she concedes: "It turns out the timing was great, between the Edwards trial and the elections."

Edwards, 59, has admitted he had an affair with his campaign videographer Rielle Hunter during the 2008 Democratic primary, which he lost to Barack Obama. In May, he was acquitted of a campaign finance charge after being accused of improperly funneling money from wealthy supporters to conceal the affair.

Siegel's novel, which she began writing about a year ago and was published this week by Weinstein Books, tells the story of Olivia Greenley, a national finance director who falls in love with her candidate, Landon Taylor, over expensive dinners with donors in Manhattan and The Hamptons.

Like Edwards, Taylor is a handsome statesman who speaks eloquently about American poverty, and whose political brand owes much to the appeal of his smart and charismatic wife.

Edwards' wife, Elizabeth, died in December 2010 after a long and public battle with cancer.

Siegel's decade in national politics began in 2000, when she worked on Hillary Clinton's successful campaign for the U.S. Senate. Four years later, Siegel, who is 35, went to work for the Democratic National Committee, and she served as northeast finance director during the 2004 presidential race.

She had no role in Edwards' 2008 presidential campaign and said she is not close to anyone in the Edwards family.

GRUELING WORK

The characters in Siegel's novel get little sleep, spend most of their days thumbing away at smart phones and struggle to maintain romantic relationships.

"It is grueling work," said Siegel, who said during one five-year period she never took more than three days off at a time. "And in fundraising, the goals are always moving, and it's always, get to that next number and get to a bigger goal."

Opportunities to rub shoulders with wealthy power brokers come in stark contrast to the humble circumstances of many campaign workers, who are paid a very small fraction of the millions they are expected to raise.

"It's outrageous what these campaigns are spending, and hopefully my book is a little bit of insight into the young people who bring in this money and the day to day craziness that surrounds these huge numbers coming in," she said.

Despite quitting campaign life, Siegel admits some habits are hard to kick, notably her BlackBerry addiction. With a laugh, she admits she wrote much of the book on her phone while riding New York City subways.

"It sounds crazy, but there's no signal and there's enough going on so you don't doze off," said Siegel.

"I would get on the subway in the morning, go out to Coney Island, get out and have a soda, go back ... and email it to myself at night," she said.

(Reporting By Edith Honan; Editing by Christine Kearney and Todd Eastham)