JK Rowling's first novel for adults, The Casual Vacancy, draws on her own experience of living on the margins of society and satirises a political landscape in which the poor are regularly cast "as this homogeneous mash, like porridge", according to a rare interview in the Guardian's Weekend magazine.

The idea for the novel, her first since the 2007 publication of the final volume in the Harry Potter series that made her a global household name and the world's first author to become a billionaire solely through her writing, came to her on an aeroplane. "I thought: local election! And I just knew. I had that totally physical response you get to an idea that you know will work. It's a rush of adrenaline, it's chemical. I had it with Harry Potter and I had it with this."

Set in the fictional West Country village of Pagford, which bears a passing resemblance to Rowling's own childhood home in the Forest of Dean, and telling the story of a parish election triggered by the death of councillor Barry Fairbrother, The Casual Vacancy investigates the agendas and infighting that fuel local politics, and the class divisions that rive even the most picturesque English communities.

The election ultimately turns on the fate of Pagford's grotty council estate, the Fields, embodied in The Casual Vacancy by the wretched, wrung-out Weedon family: mother Terri, struggling to kick her drug addiction, three-year-old son Robbie, under threat of social care, and teenage daughter Krystal.

"So many people, certainly people who sit around the cabinet table, say: 'Well, it worked for me' or 'This is how my father managed it'," Rowling said. "The idea that other people might have had such a different life experience that their choices and beliefs and behaviours would be completely different … seems to escape a lot of otherwise intelligent people. The poor are discussed as this homogeneous mash, like porridge … They talk about feckless teenage mothers looking for a council flat. Well, how tragic is it that that's what someone regards as the height of security or safety?"

Rowling's own experience of poverty – writing the first Harry Potter novel in Edinburgh cafes while she and her daughter survived on state benefits – and her emergence from it are now the stuff of literary legend.

The Casual Vacancy has featured on the bestseller list since the announcement of publication "on the strength of pre-orders alone", according to a spokesman.

Jon Howells of Waterstones, meanwhile, said of the bookseller's staff, who will take delivery of the closely guarded books on Wednesday, that "everyone's very excited and curious".

Nobody, he said, was treating the book "as if it were another Harry Potter" but, "that said, there is a little bit of that inherent craziness still there. It's an 8am embargo, and all our shops near as dammit will be open at 8am – they're usually open at 9am. I don't think it will match the first-day sales of a million-plus for the last Harry Potter, but we all expect it will be the biggest hardback novel of the year. There is competition out there, but this is JK Rowling."

滬江快訊：JK羅琳的首部成人小說《臨時(shí)空缺》（The Casual Vacancy）即將于周三上市，故事發(fā)生地設(shè)在英國(guó)西南郡一個(gè)虛擬的小鎮(zhèn)佩格弗德（Pagford），這個(gè)小鎮(zhèn)看似充滿詩(shī)情畫意，但在其平靜之下卻隱藏著激烈的爭(zhēng)斗。情節(jié)以一位名叫巴里·費(fèi)爾韋瑟（Barry Fairbrother）男子的突然死亡震動(dòng)整個(gè)城鎮(zhèn)作為開篇，人們?yōu)闋?zhēng)奪他在當(dāng)?shù)刈h會(huì)中的席位引發(fā)了一場(chǎng)“小鎮(zhèn)史上最大的戰(zhàn)爭(zhēng)”。在該書中，羅琳也帶入了自己曾身處社會(huì)邊緣的經(jīng)歷，雖然該書目前尚未開售，但已登上英國(guó)亞馬遜網(wǎng)站上最被看好的預(yù)售小說榜單。