Twenty years after Arundhati Roy won the 1997 Booker prize for her debut novel The God of Small Things, the Indian novelist’s second, The Ministry of Utmost Happiness, is set to be published in 2017, her publisher has announced.

Roy has published a wide range of nonfiction, covering topics from the US invasions of Iraq and Afghanistan to a condemnation of India’s nuclear tests, since she won the Booker in 1997 for her story of twins Rahel and Estha growing up in Kerala. But The Ministry of Utmost Happiness, which publisher Hamish Hamilton announced on Monday, will be only her second novel.

“I am glad to report that the mad souls (even the wicked ones) in The Ministry of Utmost Happiness have found a way into the world, and that I have found my publishers,” said Roy.

“Only Arundhati could have written this novel,” added her literary agent David Godwin. “Utterly original. It has been 20 years in the making. And well worth the wait.”

In 2011, Roy told the Independent of how her friend John Berger, a fellow Booker prize winner, had urged her to continue writing her second novel, but that she was distracted from it by her investigation into the Maoists in India.

“About a year and a half ago, I was with John at his home, and he said: ‘You open your computer now and you read to me whatever fiction you are writing.’ He is perhaps the only person in the world that could have the guts to say that to me. And I read a bit to him and he said: ‘You just go back to Delhi and you finish that book.’ So I said ‘OK’,” Roy told the Independent in 2011. “I went back to Delhi, and in a few weeks, this note was pushed under my door: just an anonymous typewritten note asking me to visit the Maoists in the jungles of central India.”

Roy’s publishers called her new novel “one of the finest we have read in recent times”, and “an incredible book … on multiple levels”.

“The writing is extraordinary, and so too are the characters – brought to life with such generosity and empathy, in language of the utmost freshness, joyfully reminding us that words are alive too, that they can wake us up and lend us new ways of seeing, feeling, hearing, engaging. It makes the novel new – in the original meaning of novel,” said Simon Prosser, of Penguin imprint Hamish Hamilton in the UK, and Meru Gokhale, of Penguin Random House India, in a joint statement.

“The God of Small Things was a formative book for me. The freshness of Roy’s writing and the power of the story marked her out immediately as a major novelistic talent, and it always seemed a pity that she had chosen to move away from fiction,” said Waterstones fiction buyer Chris White. “Consequently, I’m delighted that a new novel has been announced two decades after the first... I can’t wait to read it.”