"We don't like it, but this is our only possible solution," argues one of the members of the Citizen Environmental Assembly of Gualeguaychú, after he tells an Argentine family returning from Uruguay that they will not be allowed to drive through the roadblock.

"There is no other way for us to impose our wishes. If we leave the highway, the conflict is over from Uruguay’s standpoint," says another Assembly member at the camp set up at a spot known as Arroyo Verde.

"This will be lifted when the plant is removed," says the protester, referring to the paper pulp mill under construction by Botnia, a Finnish company, 22 km from Gualeguaychú. At Arroyo Verde, what used to be open countryside now has a solid tin-roofed wooden building complete with electricity supplied for free by the power company, a well and a water storage tank, and three environmentally-friendly latrines.

The first roadblock was staged in April 2005, and traffic across the bridge was blocked for much of the southern hemisphere summer of January-February 2006, causing major damage to Uruguay's tourism industry. Now it looks like a repeat is about to occur.

For nearly a month, residents of Gualeguaychú, a town of 76,000 people located 270 km north of Buenos Aires in the eastern Argentine province of Entre Ríos, have blocked traffic 28 km away from the town on Route 136, the only access route to the bridge that crosses the Uruguay River on the way to the Uruguayan town of Fray Bentos.

Only cars and trucks from nearby farms are allowed through.

However, Uruguayans who habitually shop on the Argentine side of the border, where many articles are cheaper due to the difference in exchange rates, are allowed to cross the bridge, park near the roadblock, and walk through the crowd of demonstrators, after which they get into a rental car. They come back later, laden with shopping bags and jerry cans full of fuel, which they load into their cars.

"You can see we're not as bad as they make us out to be. They constantly walk among us with their bags, and no one says anything to them, or scratches their cars," Miguel Leme comments to IPS, complaining about the criticism received by the activists.

He says it isn't true that there have been xenophobic reactions against Uruguayans, as reported by some observers in Argentina and Uruguay, although he did admit that he and his fellow activists are mad at Uruguayans.

"You know, we all have relatives over there," says another protester, pointing towards Uruguay, which can be seen across the river.

"My grandparents came to Uruguay from Europe, and my mother later moved to Gualeguaychú, which is where we were born," says Hugo Franco.

His story prompts other demonstrators to tell IPS about a brother, sister, cousin or grandparent who lives across the river in Uruguay, a country with which Argentina has especially close historical and cultural ties.

The cause of the unprecedented rift is the construction of the pulp mill near Fray Bentos, the capital of the western Uruguayan province of Río Negro. The plant, which will produce one million tons of cellulose a year, has port installations on the Uruguay River and a 120-metre high smokestack that can be seen from Gualeguaychú's most picturesque beach resort, Ñandubaysal, across the river.

Although the plant is located 22 km from Gualeguaychú, residents of that town, which depends heavily on tourism and agriculture, are worried about the risk of pollution posed by the factory and the potential impact on tourism and fishing.

Gualeguaychú is situated on the river of the same name, which runs into the Uruguay River.

Botnia says it will use the latest technology in its plant in Uruguay, in order to reduce risks to the environment. But the Argentine government continues to demand independent studies, and insists that it has not received all of the necessary information from Uruguay.

Botnia plans to use the "elemental chlorine free" (ECF) bleaching process in its plant. Environmentalists point out that while not as harmful as older technologies, ECF bleaching still involves the use of chlorine dioxide, leading to the emission of dioxins and furans, which are not only harmful to human health, but can also spread over long distances and persist for years or even decades.

There is also a newer, cleaner bleaching process, known as "totally chlorine free" (TCF), which produces no dioxins whatsoever. But industry spokespersons say it is incapable of producing high-quality paper.

The Argentine government brought a case before the International Court of Justice (ICJ) in The Hague last May, as demanded by the Gualeguaychú Assembly.

The administration of Néstor Kirchner accused Uruguay of violating a 1975 treaty for the joint administration of the Uruguay River, which stipulates that any investment on the banks of the river must be previously approved by both countries. The Argentine government also requested that the ICJ order a provisional suspension of work on the Botnia pulp mill.

But in a provisional ruling, the ICJ decided that construction of the plant could go ahead while the judges continue to consider the overall case. It may take the Court two or three years to hand down a final verdict.

Meanwhile, Botnia plans to begin operating the pulp mill in the second half of 2007.

"Sometimes I think the plant will open, and we'll still be here," confesses one pessimistic demonstrator.

As the Gualeguaychú Assembly meeting begins Friday near Route 136, it is already dark, and there are around 100 people attending. "Sometimes thousands of people show up, but today we are very few, because it's hard for people to make it," says one woman, sitting in a beach chair.

The first proposal tabled is to organise a summer camp at Arroyo Verde to keep the demonstrators’ children busy while the adults man the roadblock in January and February.

But some of the women say it is not a good idea because there are very few trees in the area to provide shade against the hot summer sun, and several men say it won't be possible to finance the necessary transportation.

Another motion that is raised and approved is to allow the bishop of Gualeguaychú, Jorge Lozano, to go through the roadblock whenever he needs to.

One demonstrator asks people to bring in books to create a library at Arroyo Verde, another suggests organising a community Christmas dinner here, and the Assembly discusses requests for permission for people with health problems to cross the river -- mainly Uruguayans heading to Argentina.

To loud applause, protester Andrés Rivas says the traffic blockade should be a bargaining chip to get Uruguay to move the plant elsewhere. Jorge Fritzler suggests installing a siren that would go off all night on this side of the river, to harass the people at the plant.

No one talks about Spanish King Juan Carlos's efforts to mediate between Argentina and Uruguay, to find a solution to the ongoing dispute.

Nor do they discuss the problems caused by the roadblock, especially since it is timed to coincide with the summer months, when tens of thousands of Argentines take their holidays in Uruguay, which has hundreds of kilometres of beautiful beaches.

Tourists from Argentina represent around 80 percent of foreign visitors to Uruguay during the summer high season, and most Argentine visitors arrive by land, crossing the bridge on Route 136 or the only other two bridges between the two countries, which are located further north on the Uruguay River. In addition, hundreds of Uruguayans who live in Argentina drive back to their home country to visit their families.

Another subject that does not come up at the Assembly meeting is Uruguay's threat to boycott January's summit meeting of the presidents of the Mercosur (Southern Common Market) trade bloc, comprised of Argentina, Brazil, Paraguay, Uruguay and, more recently, Venezuela.

The Uruguayan government's threat was prompted by the continuing roadblocks, which deal a heavy blow to the economy of that country of 3.2 million people. The administration of Tabaré Vásquez argues that the blockades violate Mercosur agreements.

But the demonstrators agree that the protests must continue until construction on the plant comes to a halt and the pulp mill is removed. When asked if they have considered other strategies to achieve that goal, Assembly member Martín Alazard responds: "Yes; block traffic across the other two bridges as well," referring to the bridges located upstream on the Uruguay River.

The Assembly was created in 2002 by Gualeguaychú residents worried about the construction of two pulp mills near Fray Bentos. But the Spanish company ENCE, which was to build the second factory, recently changed its plans, and will likely install it in the southwestern Uruguayan province of Colonia, on the Río de la Plata (River Plate) estuary.

The movement gradually grew as it was joined by environmentalists from other Argentine provinces opposed to investment by polluting industries. And as political negotiations failed, the activists’ protest measures became more and more radical.

Gustavo Rivollier, the moderator at the meeting in Arroyo Verde, explained to IPS that the Assembly is financed by donations from companies and private citizens from Gualeguaychú, as well as sales of t-shirts, caps and pins that read "No a las papeleras" (No to the Pulp Mills).

But they receive contributions from other sources as well. Early this year, two U.S. non-governmental organisations, which Rivollier was unable to identify, donated funds. So did the government of the province of Entre Ríos. Although it is publicly opposed to the roadblocks, the provincial government donated 20,000 pesos (6,500 dollars) to the cause.

"It was not for the roadblock but for the buses that took us last week to a protest march in the Plaza de Mayo in Buenos Aires," said Rivollier, who admits, however, that the Assembly "has many contradictions."

"People criticise the government, but accept the funds," he said.

Other environmental organisations support the group's demands, but distance themselves from the practice of staging roadblocks.

"Affected residents obviously have the right to say 'no’ to a factory, but we have to look at the problem from a wider angle," Juan Carlos Villalonga, director of Greenpeace Argentina, told IPS.

Paper is necessary, but cleaner production processes must be used, and on a smaller scale, and plants should be situated in places where the impact is reduced to a minimum, he argued.

"For us, direct action means blocking the entry of materials into the Botnia plant, not blocking traffic on a highway," said Villalonga.

He admitted, however, that the local residents are only noticed when they block traffic. "There have been reports and meetings, and demonstrations by tens of thousands of people, but nothing gets attention like the roadblocks," he argued.

The Kirchner administration has not directly supported the Assembly, but it has done nothing to keep it from mounting roadblocks.

An environmentalist who preferred to remain anonymous said Kirchner was wrong to adopt the arguments of the residents of Gualeguaychú, because by doing so he is evading his responsibility to engage in dialogue and find a negotiated solution to the conflict.

"The government has never opened up the debate to groups other than the Assembly, which is the most radical sector…Besides, it has double standards when it comes to investments in Argentina, which will also cause pollution," said the activist.

For now, the most determined residents of Gualeguaychú have no intention of abandoning the roadblock at Arroyo Verde, and the Uruguayan government has reiterated that it will do nothing to get Botnia to build its plant elsewhere.