# Argentina Challenges UK Over Sea Lion Oil Project at International Tribunal Argentina seeks provisional measures to halt offshore drilling in disputed South Atlantic waters. - **Source:** [Clarín – Política](https://www.clarin.com/politica) - **Published:** 2026-11-10 - **Topic:** [world](https://brifing.si/c/world) - **Original article:** - **On Brifing:** https://brifing.si/s/2a9dc209-109d-4ad9-b70c-3ce2774974f9 ## Tribunal Hearing Commences The International Tribunal for the Law of the Sea in Hamburg began hearings regarding Argentina's request to halt the Sea Lion oil project. Argentina argues that unilateral resource exploitation in disputed waters violates international law. The United Kingdom maintains that the tribunal lacks jurisdiction, asserting its clear sovereignty over the territory. ## The Sea Lion Project The Sea Lion oil field, located 200 kilometers north of the Falklands, holds an estimated 1.7 billion barrels of oil. Operated by Britain’s Rockhopper Exploration and Israel’s Navitas Petroleum, the project is scheduled to begin drilling between 2027 and 2028. Argentina warns these activities will cause irreversible damage to the marine environment. ## Argentina's Legal Strategy Ambassador Mario Oyarzábal presented four specific requests to the tribunal, including preventing the continuation of exploitation and preserving data obtained during exploration. Argentina emphasizes that this case focuses on protecting its sovereign rights over the continental shelf pending a final resolution, rather than seeking a definitive ruling on territorial sovereignty. ## Sovereignty and Jurisdiction Jurist Marcelo Kohen argued that Argentina invokes sovereignty only to demonstrate the plausibility of its continental shelf claim. The UK, led by Attorney General Ellie Reeves, rejects the tribunal's competence, citing that the islands are sovereign British territory. The UK maintains that islanders have the right to develop their natural resources. ## Procedural Mechanisms Because the UK prefers the International Court of Justice and Argentina chose the Hamburg tribunal, the case's merits must be settled by an arbitral tribunal. Hamburg can only order provisional measures if it finds the arbitral body has prima facie jurisdiction, urgency exists, and the rights invoked by Argentina are plausible. ## Appointed Ad Hoc Judges Due to the recusal of the tribunal's vice-president, Frida María Armas Pfirter, both nations appointed ad hoc judges to ensure representation. Argentina selected Raúl Vinuesa, while the United Kingdom chose Vaughan Lowe. Both judges were sworn in on Monday, just before the commencement of the two-day hearing process in Germany. ## Broader Political Context The hearing coincides with Princess Anne’s visit to the islands and upcoming debates on Argentina’s sovereignty defense bill. Meanwhile, the British government announced plans to introduce legislation protecting companies involved in the project from potential Argentine sanctions, further escalating the diplomatic tension surrounding the exploitation of these disputed natural resources. ## Anticipated Final Ruling The hearing concludes on Wednesday following a second round of arguments from both delegations. Experts suggest a decision regarding the requested provisional measures could be delivered around November 13. This outcome will determine whether the Sea Lion project faces immediate legal obstacles or proceeds toward its planned 2027 drilling start date. ## Sources covering this story - [Clarín – Política — Argentina Challenges UK Oil Exploration at International Tribunal for the Law of the Sea](https://www.clarin.com/politica/petroleo-malvinas-arrancaron-audiencias-tribunal-mar-gobierno-pidio-medidas-reino-unido_0_SsjpdLsKcV.html) - [MercoPress — Hamburg Tribunal Hears Argentina’s Challenge to Sea Lion Oil Project](https://en.mercopress.com/2026/11/10/hamburg-hearing-opens-as-argentina-seeks-to-halt-sea-lion-and-the-uk-disputes-jurisdiction?utm_source=feed&utm_medium=rss&utm_content=main&utm_campaign=rss) - [Buenos Aires Herald — Argentina Challenges UK Oil Exploration in Malvinas at ITLOS](https://buenosairesherald.com/world/international-relations/malvinas-argentina-asks-law-of-the-sea-tribunal-to-halt-uk-oil-exploration) - [Clarín – Política — Argentina Challenges UK Oil Exploration at International Tribunal](https://www.clarin.com/politica/segundo-ultimo-dia-tribunal-mar-petroleo-malvinas-argentina-responde-contraataque-britanico_0_AomDuzVg0e.html) --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._