Walking into the debating hall at a school in Bolsover during the EU referendum campaign, Kate Godfrey couldn’t quite believe her eyes. On the front row, ahead of the sixth-formers she had come to address in her role as east Midlands field manager for Britain Stronger in Europe, were five teachers wearing green ties advertising the Grassroots Out campaign.

“We lost that school years before I walked in,” she said last week. “Generally, young people nationally were backing remain 80-90%. At the end of that debate, 96% of the students said they would vote leave if they were old enough.”

When the referendum results rolled in, Godfrey’s only surprise was that as many as 29.6% of the electorate in Bolsover plumped for remain. Cameron Mitchell wasn’t at Godfrey’s debate: he went to a different sixth form. But he has no doubt how he would have voted had his 18th birthday been just a few weeks earlier. “Leave,” said the now 20-year-old, shortly after waking up from a lunchtime nap following a very early shift at Tesco. “I did think I should have had a vote then, but a second referendum would be bad for democracy, especially around here. They’ve already lost trust in politicians after all the chaos that happened in the 80s.”

“Here” is Shirebrook, a former pit village five miles south-east of Bolsover, a market town famed for its allegedly haunted castle – as well as its cantankerous Beast, Dennis Skinner, MP since 1970. The main colliery, which employed more than 2,000 men in its heyday, closed in 1993. The mine shaft was filled in and Sports Direct, the bullish discount retailer, plonked its 75,000 sq metre (800,000 sq ft) headquarters on the site. Mitchell worked there when he was 16. Most young people in Shirebrook have at least had a holiday job in the gargantuan warehouse, where a Guardian investigation in 2015 revealed workers were toiling for effectively less than the minimum wage.

Facebook Twitter Pinterest Chris Handley selling hotdogs outside Sports Direct in Shirebook. Photograph: Christopher Thomond/The Guardian

In the 13 years since Sports Direct moved in, thousands of eastern European people followed, taking up insecure agency jobs. Old miners moved out, their homes snapped up and then carved up by landlords sensing a quick buck. Bedrooms were divided in two by sheets of cardboard, sellotape on windows marking which half of the window belonged to which tenant. Living rooms became sleeping quarters, forcing new residents out into local parks to do their socialising, drinking cans of Tyskie and Żubr that had ousted stout and bitter from the corner shop.

It has led to a “divided community”, believes Mitchell, who works 25-30 hours a week at Tesco, where he is a union steward, and is studying for a degree in sports coaching and development. “Now, I go out with a Polish girl personally and my best friend is Polish, but there has been an integration problem because there’s such a large amount of migrants, they’ve got their own shops where they speak Polish, they’ve got their own little communities and there’s this divide. In many ways, I think that’s what Thatcher wanted right from the beginning. She wanted to divide and conquer, and she’s been able to do it through European Union policy,” he said.

Selling hot dogs outside Sports Direct last week, 27-year-old Chris Handley said his girlfriend used to work inside and voted leave partly as a result of her experience: “She struggled with work because her colleagues were from eastern Europe and she felt pushed out as a result.”

Along with Mitchell, Ashley Taylor, 23, is one of the youth officers of Bolsover constituency Labour party. A landscape architect, he voted remain in the referendum but has now changed his mind. “I would vote to leave now because the way the EU has treated the UK on its exit has opened my eyes up a little bit. I’ve seen what they have been doing to other countries, particularly Greece,” he said. “As a Labour party member with Jeremy Corbyn at the helm, I believe in socialist values and I believe we could generally achieve more nationally under him than we could in the EU.”

He is against a second referendum: “We’re already in a situation where domestic policies have been totally forgotten about because of Brexit. I don’t believe a second referendum would solve homelessness on our streets or improve our NHS.’”

It is that sort of talk which makes Alan Gascoyne want to wring some young necks. A former miner down Shirebrook pit, the 63-year-old is now secretary of the Miners Welfare, a community centre and charity in the town. He has been listening to Naomi Crew, the 26-year-old barmaid at the Welfare, explain why she would probably have voted leave, had she actually turned out in the referendum. “People my age, people born after 1990, don’t know what it was like round here once – the Shirebrook Alan talks about, when people looked out for each other and the pits were still open and acted like glue for our community. We’ve never known it stitched together like that,” she said. “Maybe Shirebrook people used to look out for each other, but now it’s every man for himself.”

Facebook Twitter Pinterest Naomi Crew and Alan Gascoyne at the Miner’s Welfare charity in Shirebrook. Photograph: Christopher Thomond/The Guardian

Gascoyne is similarly dismayed at the rapidly diminishing Labour vote in the area. Skinner, a lifelong Eurosceptic who announced his plan to vote for Brexit in the Morning Star, has seen his majority slashed to 5,288 from 27,149 in 1997.

The generational ties are breaking, sighed Gascoyne. “It was always the case that you voted how your dad voted and he voted how his dad voted. In one of the last elections my daughter rang me up and said, Dad, I’m thinking of voting Lib Dem. I said fine, but don’t show your face around our house any more.” He laments the lack of political education among many young people. “They don’t know that it was Labour that founded the NHS and that it is the EU which has given them many of their employment rights. They think they’ve just dropped from the sky.”

Many young people the Guardian meets in this large constituency just aren’t bothered: “Doesn’t make a difference to me, duck.” But Brexit will change Bolsover. Its biggest employer is already making contingencies for life outside the EU. Foreseeing a recruitment problem when the ready supply of young eastern Europeans is cut off, Sports Direct has been investing in some “partial automation for the Shirebrook warehouse operations” on internet fulfilment orders. This, according to the annual report, should “mitigate any potential staffing shortfall after Brexit”. We often hear that no one voted to be made poorer. They probably didn’t vote to lose their jobs to a robot either.

Constituency: Bolsover

Average age: 41

Average house price: £139,198

Percentage non-UK born: 9%

MP: Dennis Skinner

Party: Labour

MP’s intended vote on May’s deal: Brexiter Skinner is said to have decided not to back the prime minister.

Referendum result: Leave 70.4%

• The constituency profile at the end of this article was amended on 8 January 2019. An earlier version said the percentage of non-UK born people in Bolsover was 2.6%. That was based on 2016 figures from the Office for National Statistics; 2017’s data puts the figure at around 9%. This has been corrected.

