'Blackly comic' Rowling book far from Harry

JK Rowling's The Casual Vacancy concerns parish-council elections (AP)

JK Rowling was not joking when she said her next book would be "very different" to the magical world of Harry Potter. Yesterday it emerged her first novel aimed at adults would follow parish council elections in an English market town. The celebrated British author's first book in five years will be called The Casual Vacancy, and will be a "blackly comic" tale of an idyllic English town at war itself, the publishers revealed.

Details of Rowling's first book since the Harry Potter series had been closely guarded by her new publishers after initial news of the project was released in February. Bookshops were last night already preparing for what one said would "obviously be a major bestseller" after Little, Brown Book Group said the book would be published on 27 September.

The novel is expected to run to close to 500 pages, and will appear in hardback as well as in ebook format and audiobook. The Casual Vacancy focuses on the little town of Pagford, with its cobbled square and ancient abbey, which is left in shock when parish councillor Barry Fairweather dies unexpectedly in his early 40s. The publishers said: "What lies behind the pretty façade is a town at war. Rich with poor, teenagers with parents, wives with husbands, teachers with pupils." The story follows the battle for the empty seat on the parish council "in an election fraught with passion, duplicity and unexpected revelations".

In February, Rowling said: "Although I've enjoyed writing it every bit as much, my next book will be very different to the Harry Potter series."

A spokesman for Waterstones said it was "wonderful to finally know the title and release date" of the book. "It will probably [be] the bestselling fiction title this year."

He continued: "The real surprise is the plot detail; she never revealed this much in advance of the Harry Potter novels. We were all expecting some sort of crime or mystery novel, but she has, refreshingly, surprised us all."

The plot sounded like it had similarities with Mark Haddon and Alexander McCall Smith, he added. The Potter books sold over 450 million copies.