LONDONDERRY/DERRY -- Gavin Killeen says that whenever he thinks about the potential impact of a Brexit, he breaks into a cold sweat.
Killeen's printing business -- making food and drink labels and packaging for everything from bottled Guinness to dairy spread -- sits just 2 kilometers from the United Kingdom's border with the Republic of Ireland. About one-third of his exports go to Ireland, and roughly one-quarter of his staff lives across the border in Donegal.
"Northern Ireland came through a considerable period of the Troubles, where commerce and the economy didn't thrive," says Killeen, who's also president of the Londonderry Chamber of Commerce. "The thought of a Brexit and the damage it may do to our fragile economy is just not worth thinking about."
Nowadays the main indication you have crossed the border into Ireland is a clutch of gas stations where drivers from the North fill their tanks for less. Speed limits are in kilometers instead of miles, and prices are in euros -- but at Bridgend's cafe, you can still buy a cup of coffee with British pounds.
Such interconnectedness was unthinkable just a few years ago. Like elsewhere along the province's 500-kilometer border with Ireland, there was a permanent army checkpoint here during the decades of sectarian violence, known as the Troubles, between Protestant "unionists" loyal to the U.K. and largely Catholic "nationalists" who favored a united Ireland. That violence, which cost more than 3,600 lives, largely ended with the landmark 1998 Good Friday peace and power-sharing agreement, and the border security and customs checks are a thing of the past.
Return Of Borders
But along this western edge of the U.K., the border with Ireland looms large in the debate over whether the country should remain in the European Union. Some are concerned that the currently invisible dividing line, if it becomes the U.K.'s land border with the EU, will "harden" once again, harming the free flow of goods and people.
If the U.K. leaves the EU, "we will be living in a non-EU country and we will be providing services into an EU country. Will we still be allowed to do that? We just don't know," says lawyer Philip Gilliland, whose firm, located within Derry's 400-year-old city walls, does around one-third of its business in the Republic of Ireland.
"Uncertainty is bad in any business environment, and indeed in a wider sense we're already aware of inward investment decisions being stalled into Northern Ireland from the continent because they're waiting to see what happens with the Brexit result."
The "leave" campaign dismisses the border fears as just another example of "remain" scaremongering. Theresa Villiers, the U.K. government minister for Northern Ireland, and other senior members of the "Vote Leave" campaign have given assurances that there will be no change to the border if the U.K. leaves the EU.
"There has been a free-movement area since 1923," says local "leave" campaigner Kyle Thompson, referring to the Common Travel Area agreed nearly a century ago by the British and Irish governments. "There were border controls during the Troubles, but that was to stop terrorist activity.... I don't think there will be any great change to the border situation as it currently stands."
But that "no change" claim is disputed by senior figures on the "remain" side, who also say any future border arrangement will need the agreement not just of Ireland but of the other 26 EU member states, too.
And it doesn't wash with Jennifer McKeever, whose Derry family firm runs an airport bus service. "How could that possibly be?" she asks. "The ideological center of the argument to leave is based on restricting the movement of people."
She says a Brexit would be "flat-out disastrous" for Northern Ireland's budding tourism industry.
"Nine out of 10 international visitors enter the island of Ireland via Dublin, so we have to fight quite hard to get them to come all the way north," she says. "People think about Northern Ireland and unfortunately still they think about the Troubles, they think about security measures, so it's already a hindrance to what international visitors have in their head.... Northern Ireland is still quite an 'edgy' visitor destination and we don't need it to be too edgy."
Northern Ireland is the only part of the U.K. where a governing party -- the Democratic Unionist Party -- is in favor of an "out" vote. The other main parties -- Sinn Fein, the Ulster Unionist Party, and the Social Democrat and Labour Party (SDLP) -- want the U.K. to remain in the EU. Polls indicate Northern Ireland's voters lean in favor of "remain" by double-digit margins, though "leave" has narrowed the gap in recent weeks.
Border issues aside, many of the claims and counterclaims here mirror those in the wider U.K. debate.
"Remain" says Northern Ireland is a net beneficiary of EU money, receiving a little more than its roughly 375 million-pound ($530 million) annual contribution; "leave" disputes that, and says EU funding to the province is going down and will reduce further as "peace" money ends in a few years. "Remain" says leaving Europe's single market is madness for a region that sends some 60 percent of its exports to the EU; "leave" counters that trade with the EU won't stop and exports to the rest of the world are growing the fastest. "Remain" rolls out top economists and institutions who predict a Brexit would hit U.K. economic growth and lead to deep spending cuts in key public services; "leave" scoffs that those same experts have been proven wrong in the past and leaving the EU will give the U.K. more money to spend on priorities like the national health service.
For those favoring "leave" here, that notion of "taking back control" is key.
On a sunny June afternoon, Thompson sits by the city's iconic Peace Bridge, which links the more Protestant east side of the city with the largely Catholic west. Some 14 million pounds ($20 million) of EU funding went into its construction, and it was opened five years ago by an EU commissioner, but Thompson, a community worker, is unimpressed with the notion of the EU as a beneficent presence.
"There's no such thing as EU funding. It's our money that the EU gives us back, a proportion of it, and tells us how to spend it," Thompson says.
South of the city, Robert Moore grows crops including barley and raises beef cattle at his farm just 500 meters from the border. He describes himself as a "reluctant" leave voter.
He says he is annoyed by a tendency in the "remain" camp to dwell on worst-case scenarios, and says it would be in the best interests of the EU to come to a sensible deal with a post-Brexit U.K. that would minimize disruption to trade.
"The benefit for the U.K. is that we at least get to make our own decisions, we bring back control of our own country, and as far as I'm concerned as a farmer, we can create an agricultural policy that is more targeted and helps us to become more sustainable," Moore says. "We have got to get away from this business of being totally dependent on a benefit check at the end of every year from Europe."
There is one more, Northern Ireland-specific, dimension to the EU referendum: worries that a Brexit could destabilize the region by undermining the peace process. Such warnings have come from Irish Prime Minister Enda Kenny, former British Prime Minister John Major, and U.S. diplomat Richard Haass, who perhaps went the furthest with his warning this month that Brexit "could trigger political gridlock, violence, or calls for partition."
But on this issue at least, those on either side of the referendum debate in Derry appear to be in agreement: Yes, peace can't be taken for granted, but it's so deeply anchored, and has such solid support, that there is little risk of a return to violence.
"I don't think the security and the safety that has been hard fought and worked over and won would necessarily deteriorate if the U.K. were to leave," McKeever says. "But I don't think it's so secure that we can be blasé over it either."