Los Angeles - Throughout the nearly eight years of George W Bush's presidency, his demure and perfectly mannered wife Laura has acted as a counterweight to his bumbling, rash and often thoughtless style.

But her image as the perfect first lady could soon take a battering from a fictional novel based on her life that is due on shelves in early September, just as the Republican National Convention gets under way.

American Wife is the third novel by best-selling writer Curtis Sittenfeld, whose previous works include Prep, and The Man of My Dreams. The first details of the controversial tome were released Tuesday by the pop-culture magazine Radar.

Like Laura Bush, the novel's main character, Alice Blackwell, is a single child who kills a classmate in a traffic accident while still at high school and pursues a career as a librarian. But she shunts aside her Democratic leanings when she falls for Charlie Blackwell, the roguish scion of a blue-blood Republican family.

"When Charlie eventually becomes president, Alice is thrust into a position she did not seek - one of power and influence, privilege and responsibility," notes publisher Random House on its preview page.

The book departs from the known facts about Laura Bush with a series of explicit sex scenes, her discovery that her grandma had a lesbian relationship and the contention that she privately disagreed with many of her husband's policies while keeping silent out of a sense of loyalty and love.

"As Charlie's tumultuous and controversial second term in the White House wears on, Alice must face contradictions years in the making," says the book's blurb. "How can she both love and fundamentally disagree with her husband?"

Radar said the novel is "sure to send the White House into a fury."

"On the gossip front, the novel doesn't disappoint," wrote Radar. "Alice's antics are sure to have tongues chattering from coast to coast." (dpa)