Is this the greatest post-Brexit novel so far?

Miraculous visions always increase during times of Irish hardship: in the 1980s barely a week seemed to go by without a statue of the Virgin Mary waving its hand, bowing its head or shedding a tear somewhere.

In the more secular Ireland of the 21st century the moving statues were conspicuous by their absence – the stump of a newly-felled tree with a vaguely Marian outline caused a bit of a stir and prompted a minor bout of pilgrimage in Rathkeale, County Limerick, for a couple of weeks in 2009 but that was about as close as it got – but they’ve never really been much of a thing in largely Protestant Britain.

For a start most of our religious statuary was removed by the combined forces of Henry VIII and Oliver Cromwell and it’s hard to imagine any crisis, however great, prompting Greyfriars Bobby to scratch behind his ear or evoking a quick column-top twerk from Nelson.

Yet if anything was going to inspire some kind of divine apparition here then the national schism of Brexit would surely be it. Not since the English Civil Wars has there been such an entrenched binary divide on the island of Britain and the country has rarely been more febrile and simmering outside actual wars than it is now, yet there don’t seem to have been any reports of a Gove-in-the-clouds, a shimmering Julia Hartley-Brewer gazing benevolently from the skies upon Letchworth Garden City or the face of Mark Francois appearing in a pork pie. Not yet, anyway (but do check those pork pies).

A miraculous vision is at the heart of Broken Ghost, the eighth novel by Liverpool-born, Wales-based writer Niall Griffiths. Three people witness it as they make their way down the side of a Welsh mountain after an all-night rave: The figure of a woman floating in the air at the top of a ridge, surrounded by a glow in the dawn light.

The vision is only there for a moment but it’s long enough for the trio, who barely know each other, to absorb it and for the experience to influence the paths of their lives profoundly. The same west Walian mountains overlook Griffiths’ own Aberystwyth home, making him a writer drenched in the same landscape as the characters he draws so vividly from the community in which he lives.

The literary response to Brexit has focused mostly on – and been written by – the middle class. That’s no great surprise given that British literary fiction is dominated by middle class readers, writers and publishers, but it means that contemporary fiction related to Brexit can lack the viscerality at the heart of the issue, the knock-on effects on the vulnerable and impoverished whom society was already leaving behind long before the safety net of EU regeneration grants and employment protections is removed.

It’s in these stagnating tributaries of society, away from the flow of money and political discourse, that the hardest impact of Brexit is to be found. As ever the ones set to lose the most are the ones who start with the least, but in Niall Griffiths they have both a spokesman and a conduit with a finely-tuned ear and passionate sense of advocacy in the face of injustice.

Griffiths first came to prominence at the turn of the millennium with his novels Grits and Sheepshagger, searing accounts of violence, drugs and rave culture in Wales populated by Griffiths’ speciality: flawed, vulnerable characters on the fringes of society. Nobody in Britain today short of Irvine Welsh writes better such characters than Griffiths and the trio at the heart of Broken Ghost draw you in to all their doubts, dreams, fears, hopes and choices in a way that stays with you long after closing the book.

These are people on the fringes of society and on the fringes of Britain: the poorer parts of Aberystwyth on the west coast of Wales and a Brexit world far away from retweets, online petitions and Question Time. Griffiths’ Wales is one of benefit sanctions, addiction, petty crime, tawdry sexual encounters, bare-knuckle boxing and grubby pubs where “blokes stand at the bar not talking, each with a pint and a chaser in front of him. Scraggy beards and baseball caps. Bad teeth and yellow eyes”.

This is a world that shows up the paradoxical combination of community and loneliness that characterises the margins of this country. The Britain of Broken Ghost is a sidelined layer of the nation clinging to the last vestiges of industrial clannishness above the flimsiest of welfare safety nets that can be removed on a whim for shopping for a tenement block of housebound pensioners in return for a crumpled tenner, or even visiting the rehab centre of which you are an alumnus to talk to residents when you ‘should’ have been looking for work.

These are people whose names and faces are well known in their streets and towns but who find themselves entirely alone once they fall through the cracks, social and economic inequality ensuring that everyone is a hair’s breadth from that particular plunge. Brexit merely exacerbates the problem.

“The politicians blether on about the great new opportunities for Britain outside of the EU,” says recovering addict Adam. “Endless sh**e. And in all the f**kin job centres up and down the land not one thing changes. In all the bedsits, in all the pokey flats at extortionate rents, at all the foodbanks the same f**kin thing goes on. The crying and the pleading. The f**ked up children. The f**kin air is thick with it.”

When they see the apparition that morning in the Cambrian mountains the three protagonists of Broken Ghost, Adam, single mum Emma and short-fused labourer Cowley, are just about holding things together against the odds. The introspection prompted in each of them by the experience is profound and dangerous, triggering both angels and demons in all three with varying degrees of self-destruction and redemption.

With some of the grimmest sexual encounters you can imagine and journeys across Wales that will have the national tourist board’s PR department cancelling all staff leave for the foreseeable future, this is a portrait of a Britain rarely seen in contemporary novels.

Even the setting, those slate-grey Welsh mountains steeped in myth and the sublime, is grim. Griffiths’ vividly drawn descriptions of the hot summer during which the events of the book take place are not about vibrant sunsets and inspiring mountain skylines, they’re about putrefaction, decay and death, as if the landscape itself is rotting as relentlessly as the society it sustains.

“The land passes, blasted, its usually watery parts inspissated down into thick and viscous slicks, gluey gloops in which amphibians pant their last,” he writes of a train journey through country where heat-stricken toads “burp their ultimate breaths in small salt pans”.

With the parched, decomposing land itself almost as much of a character as the three protagonists, Broken Ghost might sound like a grim prospect. There is a constant, tangible anger fizzing through its pages but the book is saved well short of an ultra-Dickensian didacticism by its enormous heart.

For all their flaws and troubles we’re rooting for the characters, sensing the goodness in them and pleading with the author for their ultimate redemption despite the odds stacked against them. Emma dumps her young son on her parents to embark on a startling fiesta of boozy casual sex, Adam resorts among other things to a cruel petty theft and Cowley is permanently on the verge of inflicting sudden and raging violence on random strangers, yet their vulnerabilities and the fact they’re trying to make things better keep us firmly onside.

Broken Ghost is a fully-fledged, card-carrying Brexit novel but the fact Griffiths was working on it as far back as 2014 shows how the issues that gave us Brexit are not just related to the European Union. Brexit provided a focus for the inequality and lopsided distribution of wealth compounded by egregious government austerity that stoked a deep and profound anger in those on the receiving end.

It’s well known that Wales, a nation that has benefited greatly from EU membership, voted, like England, to leave. That vote was a howl of rage, a lashing out at the elites and the establishment, and that anger is distilled perfectly into Griffiths’ novel with an unflinching viscerality underpinned by a deeply-felt compassion.

The vision, or the “fuss about f**k all, mun. Jes-a f**kin blob in-a sky” as Cowley tells it, unleashes consequences with reverberations way beyond the trio and their community. When Emma posts a blog about the apparition it gains viral traction and before long every blissed-out raver, frazzled hippie, self-consciously impulsive student and religious whackjob in the country is converging on the mountain for an impromptu gathering at which even the most cynical of Griffiths’ creations find positivity, reunion and even redemption.

Whether the apparition was genuine or not – and the only part of the novel that doesn’t really work is the scatter of recreations of online debates about its veracity – something positive develops up there, a spontaneous community growing organically in a place where stopped dole, evictions and the bedroom tax are a million miles away. A blanket of empathetic bonhomie settles over the mountain, from strangers sharing cans and pills to cathartic encounters of deep personal significance. They even dig proper latrines. With toilet rolls and everything.

The powers that be, naturally, can’t have ordinary people rallying behind something so spontaneous, positive and beyond their control. To the authorities the many-headed monster is on the loose in west Wales and must be crushed before its virus spreads.

Orgreave is cited, the Battle of the Beanfield and the riots of 2011 as well as Brexit. The converging of the two sides towards inevitable confrontation casts a sinister shadow as the book moves to its heartrending climax.

Comparisons with Irvine Welsh are inevitable but there are other influences at work here, from Denis Johnson and Kevin Barry to Dylan Thomas and even the poetry of R.S. Thomas. It feels odd to cast Griffiths as an important new voice as he’s an old stager now, but in Broken Ghost he has produced what will surely turn out to be one of the most important and engaging novels in post-Brexit British literature.

Broken Ghost by Niall Griffiths is published by Jonathan Cape, price £16.99