Will the Brexit vote be decisive in a town that recorded one of the highest votes to leave the EU, where the sitting Labour MP was a prominent Remain supporter?

An overturned pit wheel gathers rust in the undergrowth of Mansfield’s Berry Hill Park, a discarded memorial to the town’s one-time place at the heart of Nottinghamshire’s mining industry.

Now bordered by affluent new family homes stretching in value towards the £1m mark, the same patch of ground witnessed some of the bitterest scenes of the miners’ strike on 1 May 1984, when police separated around 7,000 workers opposed to the strike from 1,000 supporters inside what was the local headquarters of the National Union of Mineworkers (NUM).

Yet, while the Labour party then managed to cling on to the Westminster seat it has held since the 1920s, today the divisions of Brexit herald the prospect of the unthinkable, as the Tories target a constituency that recorded Britain’s highest share of city-by-city votes (70.9%) in favour of leaving the EU, in the face of an MP who supported Remain.

As Labour launched its election campaign on Thursday, a former miner walking through the park where he and others had gathered 33 years ago, paused as his granddaughter played nearby and explained why he and his family were likely to vote Conservative on 8 June.

“Politicians seem to say one thing one week and another differently the next, but I think Theresa May would be one who I’d vote for,” said the man, a Leave voter for whom the scars of history still ran too deep for him for him to give his name.

His reluctance to do so was echoed by another veteran of the same scenes in the park in 1984, who passed by moments later.

“Can’t do, sorry. Those days still cause rows in pubs,” said the man, who had voted Leave on the basis that “a lot of my taxes go abroad and people come here and take what they like”.

As in many other electoral battlegrounds this year – 69.8% of voters in neighbouring Ashfield voted Leave while Labour MP Gloria De Piero supported Remain – Brexit looms large in Mansfield, if the early indications are anything to go by.

A day after Theresa May called the election, the Wikipedia entry for the town’s Labour MP Alan Meale was edited anonymously to read prominently: “Voted to Remain in Europe. Believes in immigration.”

While there is no evidence that the edit was done by Meale’s political opponents – whoever was responsible for the change used a computer with an IP address in Ayr, Scotland – local Conservatives believe the strong local support for Brexit plays into their hands. “It’s almost the perfect storm for Mansfield, to be honest, and we certainly believe we have a decent chance,” said Ben Bradley, the deputy chairman of Mansfield Conservatives.

“It’s one of the most Brexit constituencies in the country and this election is about giving Theresa May a mandate to make that happen so it’s a pretty clear argument in terms our campaign and what we need to convince people of,” Bradley added.

Meale, whose office did not respond to requests for an interview, is a former junior minister and ex-member of the Socialist Campaign Group who won the seat in 1987. In a leaked Labour document last year that appeared to rank the party’s MPs by their loyalty to leader Jeremy Corbyn, he was listed as “core group negative”, but some local activists suggest that drawing on the firepower of the expanded membership under Corbyn could be the key to saving Meale.

Local Labour party membership has increased by more than 200 since 2015.

Martin Lee, a former leader of the Labour group on Mansfield district council, who described the grassroots movement Momentum as a “breath of fresh air”, said he was cautiously optimistic that the party would hold on to the seat, which he described as having an embedded Labour vote, despite a succession of mayoral contests being won by independents in recent years.

“I was very engaged in the whole process during the 2015 general election and, on reflection, we didn’t really have a strong alternative message,” he said.

Facebook Twitter Pinterest Conservative supporter Ruth Robinson, with her dogs in Berry Hill Park, where mass clashes took place during the miners’ strike in 1984. Photograph: Fabio De Paola/The Observer

“It’s not a mistake we will make this time. There will be a strong message led by Jeremy Corbyn,” said Lee, who described the Labour leader as an asset.

Corbyn supporters believe their leader’s clear anti-austerity message will resonate in the area, particularly in large postwar housing estates such as Ladybrook, which has some of the highest levels of deprivation in England, just a stroll from Mansfield’s town centre.

Local issues too, such as the impact of a private finance initiative contract on a hospital in the area, feed into Labour’s narrative about the NHS.

In Mansfield’s historic open-air market, stall holder Mick Byrne shrugged his shoulders when asked about the economic health of the town.

“People are not spending money. When you look around here you can see the sort of shops there are – bakeries, bookies, cafes and phone shops. The place has potential but there has just been a failure to make it happen.”

Was politics the answer? “I think a lot of people have just given up on politics. Nothing ever seems to get done. People involved in the market petitioned a while back about changes but no one seemed to listen.”

However, as in other areas of the country, unknowns include the likely performance of Ukip, which came third here in 2015 with 11,850 votes against the Conservatives’ 13,288 and Labour’s 18,603. Beale’s majorities have tended to head in an upward direction since he first won the seat in 1987, when he scraped in with just 56 votes more than his Conservative challenger.

In 2015, the Conservatives’ standard-bearer was solicitor Andrea Clarke, but this time a shortlist of candidates will be imposed on the target seat by Conservative campaign headquarters.

“We don’t know who they all are yet but there are obviously some local people we’re aware of. We will probably find out in the coming days and make a final selection next week,” said Bradley, sounding less than overjoyed at the truncation of local party democracy.

While the Conservatives will be hoping to entice many traditional Labour voters across Mansfield, a particular focus will fall on the sizeable middle-class area around Berry Hill.

Walking her dogs in the park last week, resident Ruth Robinson pointed at the newly built homes on the site of the bulldozed headquarters of the Union of Democratic Mineworkers (UDM), formerly NUM offices, and spoke of how the area was being transformed by commuters and their families, who were snapping up £500,000 properties.

“My grandfather lived not far from here in a two-up-two-down with 13 children, and he worked at the pit every day,” said Robinson, who now drives past the ancestral home in her Toyota Lexus.

“Now, I think for the first time I feel really a bit more secure – and among friends I’ve also heard more positive things about Theresa May than I have about anybody for a long time,” she added.

Later though, Mick and Christine Mobey illustrated some of the complexities of this general election. The couple, who were on opposite sides during last year’s referendum, said they were impressed with both Corbyn and May.

“With Corbyn, I think he’s very idealistic and what he thinks could never ever work but wouldn’t it be lovely if it did,” she said, adding when pressed that she was likely to vote Tory.

Her husband, the son of a miner, had lost his own job when the industry closed down. He added: “It’s a tricky one. I like both of them because they have strong opinions. I think our generation might be a bit more Labour but the younger ones tend to have a different outlook.”

Location Nottinghamshire

Famous for The market town has one of the largest open-air markets in the UK, which dates back to 1227. It’s also home to the historic centre of Sherwood Forest.

Industry Mansfield suffered following the collapse of the mining industry. Mansfield brewery became the area’s biggest employer, but it too was closed when the company was taken over by Wolverhampton and Dudley Breweries. Today, many constituents work in the public sector and commute to Nottingham and South Yorkshire. Sports Direct is another local employer – though last year a parliamentary committee said working conditions at its Shirebrook warehouse resembled a Victorian workhouse.

People Rebecca Adlington, Olympic swimmer; John Ogdon, pianist and composer; Richard Bacon, TV presenter

Politics A Labour seat since the 1920s. Sir Alan Meale has been MP since 1987. In 2015 he won with 39.4% of the vote – Conservatives secured 28.2%, while Ukip won 25.1%.