A scramble by Parisians for homes in France's picturesque southwestern Basque region is fanning a nationalist backlash in a region with a troubled past.
In recent months, several properties with for-sale signs and estate agents in the region bordering Spain have been defaced with graffiti declaring "Euskal Herria ez da salgai", (the Basque country is not for sale).
Some of the slogans have taken aim at holiday-home owners from the capital, who decamped to the coast during successive Covid-19 lockdowns.
"Parisians, go home, you are the virus of the Basque country," giant posters pasted on the walls of houses in the village of Urrugne in March read.
But the anger is also directed at families cashing in their apartments in Paris and other French cities for a bigger home in a region that boasts some of Europe's top surfing beaches, with the Pyrenees mountains looming in the distance.
- Fast train from Paris -
After playing second fiddle for decades to the Cote d'Azur in the glamour stakes, the Basque country is having a moment.
"It's not necessarily rich people we see arriving, they're not Russian oligarchs with 14 million euros in a suitcase," David Buchoou of La Rochefoucauld estate agency in Anglet told AFP.
He described them instead as people with "big corporate jobs, for example" who spend a few days a week in the city and the rest with their families in the Basque country.
The floodgates opened with the launch of a new high-speed train line from Paris to the mid-way station of Bordeaux in 2017, which brought Biarritz within nearly four hours of the capital.
A massive shift to home-working since the start of the coronavirus pandemic facilitated the move, causing house prices -- and tempers -- in the Basque region to flare.
In Guethary, a fishing village of 1,300 inhabitants where every second house is a holiday home, several estate agents and homes with for-sale signs have been vandalised.
The village's mayor Marie-Pierre Burre-Cassou blames the tensions on spiralling property prices, which average 7,400 euros ($8,816) per square metre, compared with 6,670 euros in the greater Paris region.
With apartments in resorts like Biarritz now often commanding seven-figure sums, the demand for holiday homes is creeping inland to rural villages and farming communities.
An activist with the group Baiona Angelu Miarritze (Basque for the cities of Bayonne, Anglet and Biarritz), which campaigns for affordable housing, warned of growing despair among young people unable to get a foot on the property ladder.
"And when it begins to mobilise people that despair can become dangerous," warned the activist, who asked to remain anonymous.
- 'Good old ETA days' -
France's Basque country was largely spared the bloodshed seen in Spain during the four-decade quest by separatist group ETA for an independent Basque state between 1968 and 2010, in which 853 people died.
But nationalists on the French side of the border have also used violence in the past to draw attention to their aims.
Estate agents and tourism industry operators accused of "folklorising" the region were targeted in several bomb attacks in 2007 and 2008.
No-one was injured in the explosions, several of which were claimed by French Basque separatist group Irrintzi, under the slogan "the Basque country is not for sale".
Jean-Daniel Elichiry, a member of the Bake Bidea movement, which campaigned for a peaceful resolution to the Basque conflict, is among several officials warning of a risk of a return to violence.
Pointing to posts on social media expressing nostalgia for "the good old days of ETA", he said: "There's something very worrying about that."
In Biarritz, where several cars with license plates from other French regions were vandalised in May, mayor Maider Arosteguy also fears that the growing chasm between new residents and local "have nots" could endanger the fragile Basque peace process.
"The risk is that a big part of Basque youth could become radicalised," she said.
Between 2007 and 2017 the number of second homes in the French Basque country increased by 19 percent, according to the regional authority.
The figures show 54,000 homes lying empty, of which 42,000 are second homes.
Resentment over the newcomers from Paris and other French cities has been matched by frustration over a shortage of rental properties, with Airbnb blamed for shrinking supply of long-term rentals in favour of holiday lets.
To draw attention to what he calls the "speculative" nature of the rental market, a former Biarritz councillor, Eric Bonnamy, filmed himself using a grinder to dislodge boxes used to store keys for Airbnb clients on the street.
For Biarritz mayor Arosteguy such actions are "almost terrorist".
In an interview with French television she suggested introducing tax breaks for property owners who offer year-round rentals.
The activist from Baiona Angelu Miarritze urged politicians to act fast against what he described as the threat to peace from unbridled capitalism.
"We've got to a point where we have to say stop," he said.