Tina Bidzinashvili and her husband have harvested apples, quinces and peaches from the orchard behind their house since the perestroika years, when they were given it by the local collective farm in reward for hard work. But one morning recently, she woke up to find armed Russian border guards erecting a barbed wire barricade around one side of the orchard.

Her house might be in the Georgian village of Gugutiankari, the Russians explained to her, but her orchard is in the territory of South Ossetia, a small province that the international community believes is part of Georgia, but which since the Russia-Georgia war of 2008 is recognised as an independent country by Russia.

The wire is part of a process of "borderisation" by Russian border guards, during which EU monitors claim about 40km of fencing or barbed wire have been erected, augmented with hi-tech surveillance cameras mounted on poles. The fence follows a Soviet administrative boundary that was never previously applied in practice, and which runs through villages, and in some cases, through individual houses. For residents, it is the equivalent of a fence being erected to demarcate Kent and Sussex.

The process has received a sudden flurry of attention as Georgian presidential elections approach this Sunday. Locals say that the fence-building has been going on for months, but now with the vote approaching, being tough on Russia is important and politicians are rushing one after another to travel to the affected villages and show solidarity.

Georgian politicians say the border construction is one part of an increasingly provocative policy towards the country from Moscow, despite the victory in elections a year ago of Bidzina Ivanishvili, a billionaire oligarch who made his fortune in Russia and promised to improve Georgia's relations with its northern neighbour.

This year, exports of Georgian wine and mineral water, under trade embargo since 2006, were allowed back on to the Russian market. More than 10m bottles of wine have made their way across the border since the summer, according to Georgian data. An agreement appears forthcoming that would also allow citrus fruits back into Russia, which would provide a stimulus for Georgia's largely agrarian economy.

But the conciliatory noises from Tbilisi, and the gradual restoration of trade relations, has been overshadowed by the fence-building and by the Russian government's decision to invite a military pilot who bombed Georgia during the 2008 war to be one of its high-profile torch bearers in a 2014 Winter Olympics ceremony. There is public pressure in Georgia to boycott the Olympics, which take place in Sochi, just a few miles from the border with Abkhazia, another breakaway province of Georgia that Russia has recognised as an independent state.

"Taking part in the Olympics was a difficult decision for us, but we decided it was the right one," the Georgian government's point man for relations with Russia, Zurab Abashidze, said. "But these provocative actions make it difficult for us. If it continues in this way, it is possible that we will have to rethink."

Russian border guards erected a barbed wire fence around one side of Tina Bidzinashvili's orchard in Gugutiankari. Photograph: theguardian.com

A veteral political analyst, Alexander Rondeli, said the recent events proved president Mikheil Saakashvili, whose government sparked the 2008 war with Russia, was not entirely to blame for poor relations with Georgia's northern neighbour: "Ivanishvili did everything to please them and what is the result? Russia hasn't liked any of our presidents. For us, normalisation of relations means being good neighbours, for them, it means turning Georgia into a satellite."

Both sides of the border are militarised, even though the ceasefire agreement forbids it, which leads to fears that a small misunderstanding or scuffle could spark something much larger. On the Georgian side, heavily armed men in military fatigues keep guard at a camouflaged base built into the cemetery at Zemo-Nikozi, on the hills overlooking the South Ossetian capital of Tskhinvali. The police labels attached to their military fatigues fool nobody. On the South Ossetian side, Russia has built 19 border guard bases. Technically not soldiers, the border guards are nevertheless heavily armed, and part of Russia's FSB security services.

An EU monitoring mission, set up under the ceasefire agreement that ended the war brokered by then French president, Nicolas Sarkozy, patrols the borderline where Russia is erecting the fences. But the monitors have little real power. They are unarmed, and are not allowed to cross into the South Ossetian side. Instead, they make daily missions in their armoured Land Cruisers along the rutted dusty tracks on the Tbilisi-administered side of the fence, reporting back satellite co-ordinates of the new constructions. In some places the fence cuts off villages from neighbouring settlements they have visited for as long as anyone can remember,; in other places it cuts off families from the graves of their loved ones. In extreme cases, such as in Gugutiankari, it runs through individual houses.

"They told us that if we continue to farm our orchard, we'll be taken to Tskhinvali and put in prison," said Tina Bidzinashvili of the border guards, who put up the barbed wire fence that has cut off her orchard from her house. "They said the only option is if we enter South Ossetia through a legally recognised checkpoint."

The nearest checkpoint is miles away and difficult to cross. Getting to her own back garden would entail Bidzinashvili making a six-hour round trip each day. The house itself is uninhabitable – it was bombed during the war, and the family are living six to a room in the former local school, now a shelter for people who lost their homes. Their last hope was the orchard, and now that has gone too.

"We have worked hard all our lives," she said. "And now we live like pigs."