On 9 September 1981, the Norwegian football commentator Bjørge Lillelien famously celebrated his national team’s 2-1 victory over England in a World Cup qualifier. Alternating between English and his first language, he lost himself in a list of English notables and icons: “Lord Nelson, Lord Beaverbrook, Sir Winston Churchill, Sir Anthony Eden, Clement Attlee, Henry Cooper, Lady Diana … vi har slått dem alle sammen, vi har slått dem alle sammen.” The latter words roughly translate as: “We have beaten them all.”

At Manor sports complex in Fenton, one of the six towns that make up the city of Stoke-on-Trent, the early hours of Friday morning presented a similar spectacle. As the counting of ballot papers went on, local Conservative activists gazed in awe at TV screens filled with the names of once-solid Labour seats that were falling to the Tories.

On and on the list went: from Bolsover, the Derbyshire home turf of the 87-year-old Dennis Skinner, through Burnley, Derby North and the Yorkshire seat of Don Valley, to North West Durham, won by the supposed Labour leadership hopeful Laura Pidcock in 2017 with a majority of nearly 9,000, but lost on Thursday, to gasps of surprise.

By way of a climax, 4am brought confirmation that all three constituencies in Stoke – once a byword for a deeply Labour culture of potteries, coalmines, and trade unionism – were now blue. The assembled Tories repeatedly roared with delight; Labour faces, including that of Ruth Smeeth, the Jewish former MP who became a harried and marginalised symbol of the party’s antisemitism crisis, were painted with expressions of shock and disbelief.

Facebook Twitter Pinterest Ruth Smeeth and Keir Starmer canvass for Labour in 2017. Photograph: David Sillitoe/The Guardian

Such was the story of the “red wall”, the expanse of Labour-held seats running from north Wales through the Midlands to the north east of England that was held to be crucial to a Boris Johnson win, and that the Tories reduced to political rubble. Just about all of them registered majorities in favour of leaving the EU. What happened on Thursday exceeded the expectations of all the pollsters, and sealed the sense that this election heralded a possibly historic realignment.

It is often missed by accounts of Theresa May’s premiership as an endless disaster, but the groundwork was laid in 2017, when May’s Brexit offer packaged with the promise of a “strong and stable” government sent Tory vote shares in many post-industrial seats skyward. There were omens for the 2019 result in Labour’s 2017 losses of Walsall North, Stoke-on-Trent South, Mansfield, North East Derbyshire and Middlesbrough South and East Cleveland.

Then, Smeeth held on, despite a rise in the Tory vote of nearly 18 percentage points. This time, the Conservatives’ support went up by a relatively modest 2,000 votes, while Labour’s fell by 6,500, a reflection of the broader national picture. Her seat had turned blue.

Facebook Twitter Pinterest Jeremy Corbyn poses during a visit to The Oatcake Boat in Stoke-on-Trent. Photograph: Anthony Devlin/Getty Images

Two weeks ago, the Guardian embarked on a tour of four such seats for the video series Anywhere but Westminster. All four seats were lost by Labour on Thursday. We began in Wolverhampton South West, the West Midlands constituency once held by the Tory politician Enoch Powell. At a shopping parade, we spoke to about 20 people from a variety of backgrounds and could not find a single person who said they were going to vote Labour.

A teacher said Corbyn’s lack of a clear position on Brexit had simply “lost me”, while a British-Asian man whose job involved caring for children with autism said Labour no longer represented a credible opposition. There were similar stories in the eastern coastal seat of Great Grimsby, which Labour had held for 74 years. We met a primary school teaching assistant who seemed an archetypal Labour voter, but said she could not bring herself to support the party. “I really don’t like Corbyn,” she said. Her friend, who worked in the petrochemicals industry, nodded in agreement. In 2016, she had voted remain. “I don’t like his neutral stance on Brexit,” she said. “We all know he’s a leaver. Why can’t he just say it?”

In the former coalmining town of Worksop, the centre of the Bassetlaw constituency, a twentysomething chef enthused about Corbyn and Labour’s belief in the NHS, and showed us all the Labour messaging that had appeared in his Facebook feed. Here, there was a hint of the generational divide that revealed itself in the final voting figures. “I like [Corbyn],” he said. “He’s for the people, isn’t he?” But nearby, we met the proprietor of a market stall selling musical instruments; he had voted for Corbyn in 2017 but was now undecided, wondering whether the party simply had too many policies to be credible.

Other people questioned whether Corbyn would be a suitable prime minister. And why, three years after the 2016 referendum, the UK had yet to leave the EU. “They don’t listen to what we want – Brexit,” one woman in Worksop told us, with palpable anger. “What’s the point in having a democratic country if they’re not going to listen to the voters in the first place?” Set against this fundamental mistrust, promises to end child poverty and a £6,500-a-year windfall for every household were perhaps going to struggle to be believed.

Facebook Twitter Pinterest Traders at Longton market in Stoke. Photograph: Anthony Devlin/Getty Images

But there was also a sense that Corbynism had accelerated a longer, deeper story: the long tail of deindustrialisation, and the party and its wider movement’s failure to deal with the decline of the unionised factories and packed chapels that helped weave Labour into people’s lives. This struggle is borne out in Labour’s falling vote share over 20 years: in Tony Blair’s former seat of Sedgefield, in County Durham, a 71% figure in 1997 was followed by 65% in 2001, then 59% four years later, and 45% in 2010. On Thursday, when the Tories took the seat, it had fallen to 36%.

Woven into this is the death of the assumption that with enough cajolery, the party’s lost tribes will, as the trade union leader Len McCluskey recently put it, “come home to Labour”. Such an idea now seems woefully misjudged, along with an array of allied assumptions: that of the “Labour heartlands”, the party’s “core vote” – perhaps even the previously symbiotic link between being working class and supporting Labour.

Clearly, working-class communities do not represent a monolithic social bloc, and the idea that “working class” is synonymous with “white” is deeply misplaced. But over the past six weeks we repeatedly met voters in the C2, D or E social grades whose distance from Labour became less and less surprising.

In Stoke, Smeeth told us, the gravity of Labour’s defeats suggested an existential crisis, something she said she was looking forward to trying to fix. “Unless something significant changes, I don’t know what the Labour party is for. We don’t represent the people we were created to represent,” she said.

Facebook Twitter Pinterest Corbyn speaks to supporters at Fenton town hall on in Stoke. Photograph: Anthony Devlin/Getty Images

We spent an hour before the count for her seat shadowing Labour’s canvassers in the town of Tunstall. Darkness had long since fallen, and Smeeth and her comrades – including Jewish people who had travelled hundreds of miles to help her campaign – were knocking on their final doors of the night, trying to convince potential Labour supporters to go to the polling station before it closed.

At one house, a fiftysomething man answered the door. “Have you voted?” Smeeth asked. The man said he had, but not for her. For the first time in his life, he had backed the Conservatives, because of grave doubts about Corbyn. We asked him how he had felt putting a cross in the Tory box. There was a long pause. “Not good,” he said. “Not good.”

• This article was amended on 15 December 2019. An earlier version said Bolsover was in Nottinghamshire. This has been corrected.