Bishop’s Stortford had never seemed a particularly political place to Louie Corpe, a softly spoken research physicist who last year abandoned east London in favour of a quieter life in commuter country. Then came the EU referendum – and an unlikely propaganda war with the couple across the road.

“I put a Vote Remain poster in my window, and thought nothing of it,” says Corpe over lunch at Coffee Corner, a modish cafe on the town’s main shopping street. “But then the next day my neighbours, who I’ve never had a problem with, put up one of their own – except they’d taken a marker pen and replaced ‘remain’ with ‘out’. Neither of us has mentioned it since, though.”

The battle of the in/out posters provides a perfect snapshot of the Brexit debate in this sleepy, affluent market town. Bishop’s Stortford voted to leave by the slenderest of margins – a mere 622 votes, or 50.4% to 49.6%. Seven months on, the dormitory towns and rural villages of east Hertfordshire remain as stubbornly split as they turned out to be on 23 June and – albeit in courteous fashion – the debate over Britain’s future rages on.

Theresa May’s announcement that Britain will quit the single market in order to control migration has left remainers such as Corpe, a self-defining European who grew up in France and still spends most of his week in London, in no doubt as to who is winning: “Frankly, I’m feeling no better than I did in June. Since then, Brexit had been looming in the background – but May’s speech was like a punch in the gut. It feels very real all over again. It’s almost too unpleasant to be real.”

For Corpe and exiled Londoners in other commuter towns such as Hertford and Ware, May’s uncompromising approach to Brexit feels like a deliberate affront to a deeply held sense of identity. “Brexit is cutting to the core of what it means to be me,” he says. “To be told I’m no longer a European citizen means a lot. My dad still lives in France – what’s going to happen to him? Is he just a negotiating chip? The way the government are doing this feels like a betrayal.”

Fed up with carping from the sidelines, last month Corpe joined the Liberal Democrats – whose membership locally has almost trebled since June, with 18 joining in the two days following May’s speech on Europe last week. Both the Tory and Labour parties have been haemorrhaging members, disillusioned by their parties’ stances on Europe.

Immigration is lowest concern on young voters’ Brexit list Read more

Others, though, like Corpe, are political virgins. “We’re in a situation where our actions can have a massive influence on the direction of the country. Whoever you voted for before, things were broadly going to be the same in a place like this. But Brexit has changed all that – which is why I decided it was time to stop standing on the sidelines, watching and getting angry. We’re very upset, but who’s out there speaking in our voice? There was only one party doing that.”

Though East Herts Council is effectively a one-party affair – every councillor bar one is a Conservative – the Lib Dems are slowly but surely ramping up their local campaigning and believe that their unambiguously pro-Europe message can cut through.

Down the road in Ware, 1,200 people are employed at the research and development hub of pharmaceuticals giant GlaxoSmithKline, whose bosses publicly backed a remain vote but have since committed to invest £74m. But, like with Nissan in Sunderland, there is a fear locally that a botched Brexit could encourage big employers to take flight and put livelihoods at risk.

Then, said Mark Argent, who will stand for the Lib Dems against local Conservative MP Mark Prisk at the next election, the tide could turn decisively in the remainers’ favour. “There’s been a huge sense of shock – and plenty of regret – from people who felt they were just sending a message,” he said over a post-work drink at a Hertford Wetherspoons.

“Even during the campaign, the level of knowledge about what leaving was going to look like was very low. And now people are saying this isn’t what they voted for.”

South of Bishop’s Stortford, in Sawbridgeworth, a handsome Tudor village that the Beckhams once called home, May’s uncompromising rhetoric seemed to have had the opposite effect on those who had backed Brexit. As drinkers gathered in pubs to watch the inauguration of President Trump, few of those who backed his ideological lodestar showed any signs of buyer’s remorse. Art gallery owner Peyman Akhondzadeh – whose predominantly leave-voting, elderly clientele regularly complain of having fallen out with their grandchildren over the referendum result – was bullish despite concerns over economic instability. “We’ll be better off in the long term. In the short term, sure, we’ll go through uncertainty – but things will definitely get better in the long run.”

Rural England’s cause célèbre – protecting the sanctity of the countryside at any cost – was also a priority for the Iranian immigrant. “They’ve started to get rid of the green belt round here, because of the rising population [one of the government’s new garden villages is slated for construction in nearby Gilston, on the border with Essex]. I think this country’s been far too generous for far too long. We’re a very small country if you compare us with Germany, or Poland – we’re tiny.”

Facebook Twitter Pinterest ‘I can’t see anything happening that will alter my view of the EU,’ says Neville Twitchell, who voted Leave. Photograph: Graeme Robertson/The Guardian

Around the corner in Sawbridge Words, Neville Twitchell’s independent bookshop (the would-be venue of a referendum debate cancelled out of respect to the murdered MP Jo Cox), old-school Euroscepticism was high on the agenda and prominent on the shelves, with a weighty volume by anti-European sage Christopher Booker taking pride of place.

In 1975, Twitchell, now 61, was part of the thumping two-thirds majority who backed joining the Common Market – and he waited 41 years to make amends. “I felt there was too great a democratic deficit. Our national independence was slipping away,” he said, adding that remainers’ “dire prognostications” were unconvincing.

“I can’t see anything happening that will alter my view of the EU. I felt the remain side were vastly exaggerating the economic dangers. The long-term effects, I feel, won’t be disadvantageous. I’m reasonably optimistic.”

The division and rancour of the debate haven’t helped. “I do feel mischaracterised to some extent. There was a lot of misrepresentation made by both sides in the referendum, and since the result there’s been a tendency for remainers to try to characterise those who voted for leave as low-information, low-education, xenophobic people. But the voting cut across every normal indicator of voting behaviour.”

Beyond brief chats with his customers, however, Twitchell has not seen much open warfare between the two camps. Neither has Sawbridgeworth’s Green mayor, David Royle, who voted remain and was “very upset” by the result. “There wasn’t any heated debate round here. It was a very polite campaign – you’d get traces on Facebook, or letters in the paper, but otherwise not much. I haven’t changed my mind, but it’s hard to say whether we’ll feel it here. If they ran the referendum again tomorrow, it could go the other way. Enough people might have thought it wasn’t such a great idea. But it would still be very, very close.”

Corpe concedes that the area’s 50/50 split might not be as conducive to a pro-EU fightback as campaigners hope. Despite their mini-revival, the mere mention of the toxified Lib Dem or EU brand is enough to turn plenty of people off, and he fears their assiduous campaigning might end up deepening the divide rather than bridging it. Indeed, polls show Britons are more or less evenly split on whether May should prioritise controlling borders or staying in the single market.

But east Hertfordshire’s 49.6% aren’t giving up the fight – and are waiting for Brexit to hit upwardly mobile residents in the wallet. “The economy hasn’t yet exploded in the way that some people on our side said it would, but I think it will eventually,” said Corpe. “And if it becomes clear that the reality of Brexit means sacrificing our standard of living to pay for it, I think here in particular, people will start to have second thoughts.”