An Argentine federal court has ordered British and Israeli companies to halt work on the Sea Lion oil project near the Falkland Islands, opening a new legal front in the long-running sovereignty dispute between Buenos Aires and London.
Federal Judge Mariel Borruto, based in Río Grande in Tierra del Fuego, granted a preliminary injunction directing Britain’s Rockhopper Exploration and Israel’s Navitas Petroleum to refrain from starting, continuing or carrying out work linked to the project. The order covers drilling, subsea infrastructure and other activities needed to begin commercial production. The court said the suspension should remain in place until an environmental impact assessment is carried out before the relevant Argentine authorities.
Sea Lion lies around 220 kilometres north of the Falkland Islands, which are administered by the United Kingdom but claimed by Argentina as the Malvinas. Navitas and Rockhopper took a final investment decision on the project in late 2025, with commercial production currently expected in 2028. The field is one of the largest planned energy developments around the islands and is seen by the Falklands government as potentially transformative for the territory’s economy.
The lawsuit was brought by the Centre of Ex-Combatants of the Malvinas Islands in La Plata and an environmental lawyers’ association. They argued that the project poses both environmental risks and a challenge to Argentina’s sovereignty claim. The court cited concerns including possible oil spills, underwater noise, increased vessel traffic and other impacts on the marine ecosystem. Judge Borruto said the potential harm could be difficult to reverse if work were allowed to continue while the case proceeds.
The ruling, however, faces a major practical limitation. Argentina does not administer the Falklands and therefore cannot directly enforce its domestic court orders in the territory. Borruto acknowledged that implementation would depend on international cooperation and the conduct of the companies involved. Rockhopper declined to comment on the injunction, while Navitas did not immediately respond, but both companies have previously said they intend to continue developing the project under licences issued by the Falkland Islands government.
The order comes as President Javier Milei’s government steps up pressure on companies involved in Falklands oil exploration. Argentina has announced plans for tougher sanctions, filed criminal complaints against executives and companies associated with offshore development and warned that it will use legal, diplomatic and economic tools to defend its sovereignty claim.
Britain has rejected Argentina’s legal position and says Argentine domestic law does not apply in the islands. London maintains that the future of the Falklands should be determined by the islanders themselves, pointing to the 2013 referendum in which an overwhelming majority voted to remain a British overseas territory.
The injunction does not settle the sovereignty dispute or guarantee that Sea Lion will actually stop. But it raises the legal and political risks around the project and shows that Argentina is increasingly willing to challenge Falklands oil development through its courts as well as through diplomacy.
