British author Hilary Mantel, a double Booker Prize winner, whose latest books are set in the Tudor court, dismissed Kate Middleton as a “machine-made” princess, “designed by committee”.

Hilary Mantel, 60, compared Kate Middleton unfavorably to both Anne Boleyn – one of her historical heroines – and to Princess Diana, insisting both had more personality.

The author said Kate Middleton had gone from being a “jointed doll on which certain rags are hung” to a woman whose “only point and purpose” was to give birth.

Hilary Mantel said the Duchess of Cambridge “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”.

Now British PM David Cameron, while on a trip to India, has reportedly waded into the row to support Kate Middleton.

David Cameron said that Hilary Martel is “a great writer” but described her comments on the Duchess as “a hurtful thing to say”, according to reports.

He described the comments about Kate Middleton as “completely misguided and completely wrong”.

The head of a charity supported by the Duchess of Cambridge has hit back at Hilary Mantel’s extraordinary attack on her, saying she is an “intelligent” woman who is proving to be a huge asset to the causes she backs.

Nick Barton, chief executive of Action on Addiction, said the Booker prize-winning author was entirely wrong to characterize Kate Middleton as a clothes horse whose only purpose was to give birth.

Kate Middleton, who is almost halfway through her pregnancy, carried out her first official engagement of the year this morning when she visited Hope House, a 22-bed residential facility for women from all over the country to get over addictions to drugs and alcohol.

Hilary Mantel attacks Kate Middleton branding her a plastic princess

Action on Addiction is one of five charities of which the Duchess is patron, and she spent her time there speaking to women who are in recovery and congratulating those who are on the road back to sobriety.

Her visit came after the lecture, where Hilary Mantel said Kate Middleton was quite unlike Anne Boleyn, who was “a power player, a clever and determined woman”.

Hilary Mantel contrasted the Duchess’ appearance to Prince William’s mother, Diana, “whose human awkwardness and emotional incontinence showed in her every gesture”.

Hilary Mantel, the author of Wolf Hall and Bring Up The Bodies, the acclaimed novels which detail the failure of Henry VIII’s wives to produce an heir, used a lecture to examine the prospects for the future queen consort.

The author said that when she first saw Kate Middleton, she struck her as “a shop-window mannequin, with no personality of her own, entirely defined by what she wore”.

Prince William’s wife-to-be was as “painfully thin as anyone could wish, without quirks, without oddities, without the risk of the emergence of character”.

Hilary Mantel added: “Presumably Kate was designed to breed in some manners.

“She looks like a nicely brought up young lady, with <<please>> and <<thank you>> part of her vocabulary.”

Hilary Mantel also spoke of Kate Middleton’s appearance in her first official portrait since marrying Prince William, painted by Paul Emsley, which was unveiled last month.

She said: “Her eyes are dead and she wears the strained smile of a woman who really wants to tell the painter to bugger off.”

Hilary Mantel went on to say that female Royals were “at the most basic… breeding stock, collections of organs”.

St James’s Palace last week criticized a magazine for printing pictures of Kate Middleton’s baby bump taken during a break on the Caribbean island of Mustique.

And they were furious last year when pictures of her topless on holiday were printed in Italy – saying “a red line had been crossed”.

But Hilary Mantel suggested Kate Middleton could have few complaints about private pictures of her being taken on holiday – observing: “The royal body exists to be looked at.”

“Some people find them endearing; some pity them for their precarious situation; everybody stares at them, and however airy the enclosure they inhabit, it’s still a cage.”

Ingrid Seward, editor-in-chief of Majesty magazine, said Mantel’s comments were unfair.

Hilary Mantel studied law at LSE and Sheffield University, before becoming a novelist.

She is author of more than a dozen books, including Wolf Hall and Bring Up The Bodies, the first two parts of a trilogy about King Henry VIII’s adviser Thomas Cromwell, both of which won the Man Booker Prize.