Actress Natalie Portman is reportedly upset by author Rachel Cusk's new novel, "Life of M," which insiders claim paints an unflattering portrait of the star as an out-of-touch diva. Sources close to Portman told the Daily Mail that the actress is "horrified" by the book, which is set to be released later this month.

Portman's representatives have denied that the actress was involved in any publicity stunt surrounding the book, stating that she is "not happy" with the portrayal. A friend of Portman's described her as "a very private person" who moved to Paris to escape the spotlight, and that Cusk's book has "really pissed her off."

"She thinks it is a real low blow and is horrified about the rumors she was in on the book in some way, which she certainly was not," the friend told the Daily Mail. "The celebrity in the book is nothing like her, she is far from a diva, she is a quiet bookworm."

Despite claims that Portman has taken the controversy in stride, sources insist she is distressed by the book, which is speculated to be based on her life and career. The novel reportedly features a film star, identified only as "M," who is portrayed as self-absorbed and out of touch. Elements within the book, such as "M" appearing in an advertising campaign "wreathed in pink flowers," are seen as direct references to Portman's long-standing role as the face of Christian Dior's Miss Dior fragrance.

Further parallels drawn in the book include "M" being a child star, a sexually ambiguous relationship in her first film that her mother had cut from the script, and a role in a film about a famous family that resembles Portman's portrayal of Jackie Kennedy. The book also depicts "M" struggling with a low opinion from ballet teachers and jealousy of a rival actress, echoing Portman's Oscar-winning role in "Black Swan."

However, Cusk's detractors argue that the book goes beyond professional parallels, offering a "withering portrait" of a "pitifully self-absorbed and alienated star." The character "M" is described as irritated by ordinary people, coldly calculating, and unable to relate to others, living in an impersonal home and always performing.

Sources close to Portman contend that the character bears "absolutely no resemblance" to the actress, describing her as a "kind and warm person" who is a "quiet bookworm." They also highlight Portman's belief in "girl power and sisterhood," suggesting the book is a "gross violation of her code."

Cusk, a Canadian-born novelist, has faced similar accusations of insufficiently fictionalizing real people in her previous works. Her 2009 novel "The Last Supper: A Summer In Italy" was reportedly threatened with a lawsuit for breach of privacy. In 2017, Scottish writer Damian Barr accused Cusk of "looting" his personal revelations for a character in her novel "Transit."

Despite the controversy, Cusk has not officially commented on whether "M" is based on Portman. Some have defended the writer, pointing to details in the book that do not correspond to Portman or arguing that the narrator's speculation makes it a work of fiction.

Amidst the speculation, Portman is reportedly focusing on her pregnancy, due any moment, and her relationship with boyfriend Tanguy Destable. A source told the Daily Mail that Portman "will not address the book and is writing it off as an unfortunate phase of her life."

Some critics suggest that if Portman truly champions literature, she should appreciate Cusk's contribution. Others posit that her reaction might confirm a view of her as a "beautiful if painfully bland actress" whose bookishness is an affectation.

"Life of M" is Cusk's first novel since her critically acclaimed "Kudos" in 2018. Cusk herself has previously conceded to oversharing her own life in her books, stating after writing "Aftermath" about her divorce that the "divide [between life and the book] was completely breached."