Four years ago in Shildon, County Durham, Michael O’Neill stumbled upon a long-forgotten piece of local heritage. In a corner of the small town’s railway museum, tucked away in storage and forgotten, was the old Bishop Auckland railway union banner, believed to date back to 1915. A classic of its genre, this piece of early labour movement iconography depicts smartly uniformed rail workers gazing towards a utopian future. Below there is a version of the final paragraph of the Communist Manifesto: “Workers of the world unite! You have nothing to lose but your chains. You have a world to win.”

O’Neill, 44, is from Bishop Auckland. Over the years he has been involved in numerous community projects, most recently raising funds for a memorial to Cpl Lee Brownson, a local boy who was killed in Afghanistan in 2010. Through O’Neill’s efforts, the railwaymen’s banner is now proudly on display at the Four Clocks Centre in Bishop Auckland, alongside a small exhibition telling the story of the world’s first steam locomotive railway line, which passed through the area.

For a lifelong Labour voter, this was an act of loving commemoration. But in less than two weeks time, O’Neill will vote Conservative in the general election. “I’ve been a Labour member and my family has always voted Labour,” he says, “but the party around here has turned nasty in my opinion, since the Brexit referendum. I voted to leave, but leave voters are being called racist and far right, which is not how it is. We have a local Labour MP in Helen Goodman who should be standing up for democracy. It shouldn’t matter that she voted remain.”

The significance of what would amount to a political revolution in the town everyone calls Bishop is not lost on O’Neill: “Ten years ago, a Conservative MP wouldn’t get the time of day on the doorstep around here. This place is steeped in memories of the Thatcher era and the mines and the steelworks. But I’m not alone in turning against Labour.”

Last week, the most comprehensive poll of the election campaign so far predicted that Goodman’s tiny majority of 502 will be overturned on 12 December, and that 25 year-old Dehenna Davison will become the first Tory to represent the area. Bishop Auckland voted 61% in favour of leave and Davison’s Twitter hashtag incorporates the Boris Johnson mantra: “Get Brexit done”. Though a Brexit party candidate is standing, the seat is acknowledged to be a two-horse race.

In a region which feels its collective voice and concerns have been ignored since the mines closed and other industries went the same way, Labour leave voters saw Brexit as carrying the possibility of social renewal. The failure of the party to fully endorse the referendum result is seen by former supporters like O’Neill as both dishonourable and a sign that the party has moved away from its working-class roots. Goodman’s much-diminished majority – in 2005, it was over 10,000 - also suggests Labour is paying the price of long-term local incumbency in an era of deepening disillusionment across the region.

The mining town of Spennymoor and the surrounding pit villages sit within a constituency that was part of one of the richest, most culturally vibrant coalfields in Europe. Twenty-five years after the last pit closed, there is a palpable longing to restore a lost sense of purpose and cohesion; and an anger at the way that the infrastructure of communal life has been allowed to corrode and decay.

Bernadette Rush in her bridal shop: ‘A lot of places in the high street are owned by absent landlords and they are just left to rot.’ Photograph: Richard Saker/The Observer

In Bishop Auckland, the closure of the local A&E has become a major election issue. Davison is promising to re-open it. Sarah Bryson, a mental health nurse who commutes to work in Durham, is sceptical. “Brilliant, but how?” she says. “It would be great to have a fully functioning hospital on every doorstep, but that’s just not where we are at.”

Nevertheless, Bryson sympathises with those who campaigned against the closure. “This town and surrounding areas have lost their connection to a lot of things; the idea of the closure of a hospital seems to sum that up in people’s minds. It gives a sense that somehow this area isn’t worthy.”

The high street, one of Britain’s longest, has been in steep decline for a while. This month, Bernadette Rush will vacate No 136, where she has run Image, a bridal shop, for eight years. “There’s been a huge dip in sales,” she says. “People are either buying on-line or from out-of-town suppliers who are manufacturing dresses offshore far cheaper than I can buy them for.” For the past few years, Rush, a skilled seamstress, has made her living from making alterations to dresses bought elsewhere. She now plans to work from home, freeing herself from the overheads.

Twenty per cent of town centre business units are vacant, including the Victorian co-op building which, until 2017, housed Beales department store. The site has been earmarked for either a hotel or apartments, but for now it sits like an open wound in the centre of Bishop Auckland. “A lot of places in the high street are owned by absent landlords and they are just left to rot,” says Rush. “They just look a mess. It’s very unsightly.”

Like many other residents, Rush hopes a singular turn of events may yet turn the town’s fortunes around. Last month, Auckland Castle, the medieval home of the prince bishops of Durham, was opened to the public. Restored, its 18th-century Long Dining Room displays work by the 17th-century artist Francisco de Zubarán, sometimes known as the “Spanish Caravaggio”. Elsewhere, visitors can see Nicolas Poussin’s The Triumph of Pan, which is on loan from the National Gallery.

The slightly surreal Auckland Project’ is the £150m brainchild of Jonathan Ruffer, a City investor from Stokesley, near Middlesbrough. Ruffer bought the Zubaráns from the Church Commissioners, which was intending to sell them off. As well as restoring the castle he is regenerating the adjacent marketplace, where a miners’ art gallery and a 29-metre viewing tower were opened last year. A Spanish art gallery, in homage to Zubarán, is planned and the market square’s pubs have been bought and closed, before conversion into hotels and restaurants. Ruffer has also funded the annual Kynren, an outdoor pageant chronicling 2,000 years of English history.

Below left: Beales department store closed in 2017.

Below right: One of the restored rooms in Auckland Castle. Photograph: Richard Saker/The Observer.

Main: The Auckland Tower, which has bemused some but not others. Photograph: Richard Saker/The Observer.

Bottom left: The millionaire Jonathan Ruffer, pictured in 2014. Photograph: Owen Humphreys/PA.

Bottom right: The Auckland Project is the £150m brainchild of Jonathan Ruffer. Photograph: Richard Saker/The Observer.

The tower, in particular, has been greeted with bemusement by some. But in the Fifteas Vintage Tearoom, in the market square, John Phelan is happy to sing Ruffer’s praises. Phelan is a local historian who lives in the nearby village of Howden-le-Wear, which is in the neighbouring constituency of North West Durham. “It’s very exciting,” Phelan says. “He’s turning Bishop Auckland into a place of culture. One to rival Durham even. History might be the new thing to bring some hope and a feeling of community back to Bishop.”

A sense of renewal is desperately required, Phelan adds. “You’d like to think as life went on things would get better, but they’ve not.”

An inveterate romantic, this year Phelan is sending out Christmas cards which carry a photograph of the FA Amateur Cup final in 1954, when ‘Bishop’ played local rivals, Crook Town, in front of a Wembley crowd of 100,000. His father took him, aged four, to the match on a train that went directly from Crook to London. But the nostalgia comes with a sharp edge. Echoing a theme that comes up continually in the area, a lack of public transport, Phelan says: “A lack of funding from central government has knocked County Durham back generally. The buses have been cut and you barely get any after 6pm. That impacts on people’s lives. There are villages that are practically cut off in the evening now, for people who don’t drive.

“The cuts to street-lighting have meant that rural areas are pitch black at night. I know a woman who is frightened to walk her dogs because it gets so dark. Austerity has chipped away at the quality of life of communities.”

Phelan will vote Labour but is not holding out too much hope. “I won’t be surprised if the Conservatives tip it their way this time. The Labour vote isn’t as loyal as it once was and some people are not so keen on Helen Goodman.

“I tell people who are thinking of voting Conservative, ‘You’re shooting yourself in the foot. Look at the cuts. The Conservative governments haven’t done anything for this area.’ But the Brexit issue has been very bad. If I’d have voted for Brexit I’d be angry with Labour. They’ve dillied and dallied on it. It’s been weak. A Labour leader should have said: ‘People have voted to leave and that’s it whether you like it or not.”

Ryan Lamb (23). Photograph: Richard Saker/The Observer

Whether that would have won the vote of Ryan Lamb, a 23-year-old labourer from Spennymoor, is doubtful. Lamb voted leave in 2016 and Tory in the general election a year later. He intends to do so again this time round, though he has no faith in the pledges being made on either side of the political spectrum.

“They all talk a load of shite,” he says. “I don’t believe Boris Johnson is going to put my wages up. I don’t believe he’s going to put more money into the NHS. But [Jeremy] Corbyn’s crap. Someone sent me a Piers Morgan interview on Facebook. He showed Corbyn up. In the end, we were meant to leave on Halloween and we didn’t. It comes down to that.”

Andrew Smith is an 80-year-old former NUM activist who worked at the Mainsforth and Ferryhill pits. He now volunteers at Spennymoor’s mining museum, sometimes assisted byErnie Foster, 81, who was also active in the union. The small museum is an affecting cornucopia of mining memorabilia: there are banners of course, but also detonators, cables and a trophy awarded at the Spennymoor gala pit pony competition in 1956.

A detail from a panel in Spennymoor town hall. Photograph: Richard Saker/The Observer

Smith views the forthcoming election, and the fraying of loyalty to Labour, with sadness and trepidation. “It makes you angry,” he says. “It makes you frustrated that people who have gone through the times that you went through, are thinking like this. It’s not just the young. It takes a lot to get through to people; to explain what the real problems are. The media don’t help with their bias; people say they don’t like Corbyn. But when you ask them they don’t really know why.”

A December election is not ideal for octogenarian activists: “We’d like to get out leafleting for Labour,” says Smith. “But we’re getting on now.” Foster chips in: “The main thing is that we can’t have that lot in round here – the Tories. That can’t be allowed.”