Anger as author labels Catherine a 'machine-made' doll with 'plastic smile' Catherine, Duchess of Cambridge is photographed by members of public on September 12, 2012 in Singapore. Author Hilary Mantel describes Catherine as "precision-made, machine-made" She contrasts Prince William's wife with Diana, who she says showed human emotions UK newspapers criticize Mantel's comments as cheap and venomous Mantel has twice won the Man Booker prize for historical novels focused on the Tudors London (CNN) -- An award-winning author has whipped up controversy by describing Catherine, the Duchess of Cambridge, as a "machine-made" doll with a "plastic smile" who lacks the personality and human frailty shown by Princess Diana. Hilary Mantel, who has twice won the Man Booker prize for her historical novels set in Tudor times, made the comments in a talk for the London Review of Books entitled "Royal Bodies." READ: Hilary Mantel becomes first woman to win literary prize twice The furor over her comments came as Catherine prepared to carry out her first official engagement this year, with a visit to an addiction treatment clinic. The duchess, who is patron of the charity that runs the clinic, Action on Addiction, was briefly hospitalized late last year with acute morning sickness. She and husband Prince William are expecting a baby in July. READ: Prince William, Duchess of Cambridge's royal baby due in July In her lecture, Mantel described how Catherine's public image was first defined by her clothes, and then her pregnancy. Before she became a mother-to-be, she was a "jointed doll on which certain rags are hung," Mantel said, and "a shop-window mannequin, with no personality of her own, entirely defined by what she wore." READ: The Duchess of Cambridge's fashion secrets revealed The author also suggested the chief attribute brought by Catherine to her royal marriage was good manners, adding that the duchess "appeared to have been designed by a committee and built by craftsmen, with a perfect plastic smile and the spindles of her limbs hand-turned and gloss-varnished." And Mantel contrasted that with the potential for disaster that Diana, the late Princess of Wales and mother to William and Harry, carried with her, saying Kate was "irreproachable: as painfully thin as anyone could wish, without quirks, without oddities, without the risk of the emergence of character." Unlike Diana, "whose human awkwardness and emotional incontinence showed in her every gesture," Mantel said, Kate appears to be "precision-made, machine-made." Mantel was also critical of the public and the media, who she suggests, place royal women under unhealthy scrutiny, particularly when it comes to producing a royal heir. Nonetheless, her words attracted fierce criticism Tuesday. In the Telegraph newspaper, women's editor Emma Barnett dismissed Mantel's comments as "not only unfounded, but incredibly cheap." It is very early days for Catherine as a royal and her image is being carefully managed, Barnett points out. "She has ample time to develop her public persona and become a fully-fledged role model if needs be," she said. Nor does Catherine have the luxury of responding to criticism, she added. As a fully paid-up member of the royal family, she can only respond by doing the very same thing Mantel has criticised her for: staying quiet. The Daily Mail also blasted Mantel's comments as "an astonishing and venomous attack." Mantel last year became the first woman ever to twice win the Man Booker prize, for her novel "Bring Up the Bodies." She previously won in 2009 with Wolf Hall. Her novels focus on the Tudors -- and in the lecture she draws a parallel between the current fascination with Catherine's body and the public gaze under which the wives of Henry VIII sought to produce a male heir. Last week, an Italian magazine provoked uproar in the UK media when it published pictures of a bikini-clad Catherine on vacation, with her "baby bump" visible. Palace officials said they were disappointed by what they said was a clear breach of privacy. READ: Magazine defends photos of pregnant, bikini-clad Duchess of Cambridge "Long before Kate's big news was announced, the tabloids wanted to look inside her to see if she was pregnant," Mantel said. Cheerful curiosity can easily become cruelty. It can easily become fatal. We don't cut off the heads of royal ladies these days, but we do sacrifice them, and we did memorably drive one to destruction a scant generation ago. The institution of monarchy may be irrational, Mantel added, but those outside don't have to forget their principles as they observe the "entertainment" the royals provide. I'm not asking for censorship. I'm not asking for pious humbug and smarmy reverence. I'm asking us to back off and not be brutes," she said.