'Harry Potter' author JK Rowling's dark new novel 'The Casual Vacancy' divides critics

First reviews of Harry Potter author JK Rowling's novel for adults on Thursday praised its Dickensian scope and social message, but warned the gritty, even obscene tale was a far cry from Hogwarts.

Shortly before the release of the hotly awaited "The Casual Vacancy", several reviewers said they were taken aback to read grimy scenes of sex and drugs, but added the author's most vivid writing was on the familiar ground of adolescence.

"I had just read a passage written by the world's favourite children's author in which a teenager is raped by her mother's heroin dealer, a man who may well be the father of the girl's own three-year-old stepbrother, although it's hard to know for sure when the mum concerned is a prostitute," wrote Allison Pearson in the Daily Telegraph.

She added that the novel, a story of poverty and politics in an English village -- of which a million copies have been pre-ordered -- was "sometimes funny, often startlingly well observed, and full of cruelty and despair".

But the Mirror tabloid labelled it "Harry Potter and the Goblet of Filth", warning the author famed for her stories of young wizards was "sure to face stern criticism for featuring the C-word and F-word hundreds of times".

Set in the picturesque fictional village of Pagford in southwest England, the black comedy deals with the fight to fill a slot on the parish council after the incumbent's sudden death, and hinges on the fate of a squalid housing estate.

Kept closely under wraps until publication, it hits bookshops on Thursday and is expected to be Britain's top-selling fiction title this year.

In the Independent, Boyd Tonkin called it a "song of freedom" after Rowling's seven children's books, which made her the world's first billionaire author.

While decrying the novel's "clunkily satirical set-pieces", he said it "picks up passion, verve and even magic" when dealing with its teenage characters.

"All the social and hormonal turbulence that the later Potter volumes had to veil in the euphemisms of fantasy appear in plain sight here," he wrote. "The novel builds into a vividly melodramatic climax with these kids at its heart."

But the Guardian's reviewer Theo Tait labelled the edgier scenes "superficial excitements", saying the novel created a sense of "slight anti-climax" despite its "richly peopled, densely imagined world".

And writing in The Times, Erica Wagner said the book was founded on "the idea of the novel as a force for social good" but could be "a tiny bit dull".

For the Telegraph's reviewer, however, a top concern was the risk of the book falling into the wrong hands.

"In the coming days, along with thousands of parents around the world," she wrote, "I will have to do something that offends our best instincts: I will try to stop my children reading a book."