Harry Potter has been knocked off the top spot by the raunchy novels by E L James

Harry Potter may have cast a spell over the nation since 1997, but today, EL James’ raunchy Fifty Shades trilogy whipped the children's classic into submission with James becoming the bestselling author of all time on Amazon.co.uk. Outselling the entire seven-book Potter series, James, who has sold in excess of 4 million copies of her books in print and on Kindle since they went on sale in March 2012, has left the nation split between those who hate and love the BDSM bestseller. The sexually explicit 'mummy porn' has polarised opinion between those arguing that her work is shoddily written and derivative to women, and those who contend that it is sexually liberating. More... • Fifty Shades of Grey brings out Britain's 'hidden' sexual drive • Fifty Shades author reveals where she learnt about bondage • Lashings of Fifty Shades style books to hit shelves

Rowling was the literary phenomenon of the last decade, James looks certain to take that mantle now Gordon Willoughby, Director EU, Kindle

Sadly for Harry Potter, the country is more enamoured with Christian Grey’s wince-inducing Red Room of Pain, rather than Hogwarts' potions class and the whomping willow. The books revolve around the explicitly detailed relationship of protagonists Christian Grey and Anastasia Steele focusing on their sadomasochistic sexual encounters. “If JK Rowling was the literary phenomenon of the last decade then EL James looks certain to take that mantle in the current decade,” said Gordon Willoughby, Director EU, Kindle. “In just four months, EL James has become Amazon.co.uk’s biggest selling author of all time which is truly remarkable when you consider that we’ve been selling books for almost 14 years,” he added.

Meanwhile, it has been revealed the country could be faced with a baby boom in the wake of the novel's content being recreated in bedrooms across the nation. Online forums, including Baby Center have been teeming with mothers' revitalised sex stories – thanking the erotic novel. Linda Murray, global editor in chief of Baby Center told Good Morning America: "Reading 50 Shades of Grey is acting like an aphrodisiac for women. "It's putting them in the mood more frequently and they're having more sex and they're ultimately getting pregnant faster," she added.