It is just after 8.30pm on a Tuesday, and Howard Jacobson is sitting at his desk in London, his computer still on, waiting to finish his working day. On an ordinary evening he would already be out walking the streets of Soho or having a glass of wine and watching a box set, but he has been expecting my call and is still in writer mode. Or should I say talker mode?

Despite a whirlwind of publicity since the publication of his latest novel, J, which was brought forward after news broke, in early August, that it had been longlisted for the Man Booker Prize, he is giddy and garrulous, almost breathlessly voluble, about writing, reading, literary prizes and anything else that our conversation chances on.

"Do you want me to slow down?" he asks as he hears my fingers clicking against my computer keyboard. I am struggling to keep up, it is true, but I don't want him to pace himself. The restless patter is far too interesting. It is also perfectly reflective of his inexhaustible imagination, revealed over 13 novels, which have set the universal dramas of love and loss against the backdrop of the book industry (The Act of Love, Zoo Time), a football club (Coming from Behind), a table-tennis tournament (The Mighty Walzer), the BBC (The Finkler Question) and now, with J, an apocalyptic natural disaster.

Jacobson is the first to admit that J is a radical departure of form for him. "I think it's fair to say that I have what people would call my signature voice," he says. "And people would call it a rather masculine voice, full of self-deprecation, anger and comedy. I have always talked about the importance of comedy, the seriousness of comedy, how comedy helps to cut away at things. And it has served me well and given me pleasure. But my whole writing apparatus didn't want to do that this time. I found other voices than what would be my normal pantheon of voices; different modes of expression. There was more story than I normally have, and there was nothing to cut away this time for comedy. All of a sudden it was a dystopian novel, leading into genres or byways I never would have expected, and it totally took me out of my comfort zone."

J takes readers out of their comfort zone, too. Set in the near future, it portrays a society that has survived near-extinction but is still defined by an "equilibrium of hatred". What happens if you eradicate the object of hate, Jacobson asks in J. As history has proved, the hatred lingers on.

But J is not just an uncharacteristically bleak book. It is also challenging in form. One of its central characters is a philosopher, and the pages teem with ideas and voices. There are misleading clues. There are interchapters in which Jacobson details the history of pogroms and massacres. There are even different typefaces. At times this refusal to settle in style makes for a plodding and perplexing read, but the denouement reveals a hidden logic, and the book climaxes with a brilliant literary (and philosophical) coup.

Jacobson credits winning the Booker prize in 2010, for The Finkler Question, with giving him "the confidence to move away from something I knew I could do well. I wouldn't have thought about it at the time – I am not a conscious sort of writer – but maybe I was being constrained from going further.

“No matter how arrogant a writer seems, he is always uncertain. Confident people don’t write novels. They become bankers or footballers. And no matter how energetic you seem, you never know how good you are. Even if people tell you, there is still a diffidence, because there is no reason you should believe them. So the imprimatur of your peers saying you are good is really important.

"I didn't consciously feel like that, but now the leap has been taken – see how I am using the passive tense? – it seems to have made a bigger difference than I thought. I don't know if I would have written a book like J if I had not had that sort of success."

If J reveals a different side to Jacobson, he can also see an element of it that runs back to his first work. "My books have always tended towards the dystopian," he says. "As in, This is what the future is like in exaggeration – which is really saying, This is what we are going to be like next year. You could say it's a sort of comic prophetic voice. In another age I can imagine myself going around streets of old Jerusalem or Athens, shouting, 'We are about to witness the fall of house of Atreus.'

"My very first novel," he says by way of illustration, referring to Coming from Behind, from 1983, "was a campus novel, but it was the end of all campus novels, the end of university altogether. Zoo Time was also a sort of dystopian novel, with agents in hiding from clients and so on. It was a hyperbolic version of publishing, yes, but publishers liked it, because they recognised it."

You could say, then, that "J is the ultimate fulfilment, even if the form or manner of it is surprising. But, still, it is no surprise that I should be telling a story about apocalypse. You can't be a Jew and not have the shadow of genocide follow you."

This is the first time Jacobson’s cultural heritage reveals itself in our conversation, although he is more often named as a Jewish writer than as a writer. “Yes, I am Jewish, and I write from my own experience, but people always think that because of that they should associate me with the Americans – Philip Roth and so on – Kafka, the Russians et cetera.

"But I am really very British in my tastes. I am really just an old-fashioned English-literature man: Austen and Dickens; Lawrence and Eliot; Shakespeare. And for all that my books aren't like [those writers], deep down they are. My Manchester voice, my working-class stuff, even the style of J , these are really just grafted on to a very old-fashioned, English sort of novel."

There is nothing old-fashioned about J, however. Indeed, if its postmodernist form makes it particularly of the moment, so does its subject matter, and the crisis in Gaza is never far from the reader's mind as J's bleak futuristic vision unfolds.

Jacobson is unwilling to comment on the political nightmare in the Middle East. “Of course there are clear echoes with the current situation,” he says briefly, closing the conversation, “but I don’t want to lay any claim to topicality or to the horrors going on there. I belong to that school which believes that a novelist should shut his mouth and not have opinions – should just get on with the business of writing.”

J is published by Bloomsbury