Argentina challenges UK maritime claims in Falklands oil hearing

Argentina challenged Britain’s position on waters surrounding the Falkland Islands at an international tribunal in Hamburg, arguing that the sovereignty dispute does not give London unrestricted authority over offshore resources. Lawyer Marcelo Kohen compared the British approach to a historic doctrine asserting the crown’s dominion over extensive ocean areas.

Representing Argentina, Kohen invoked the concept of Dominium maris Britannici to criticise what he portrayed as an outdated colonial position. His argument placed the unresolved territorial dispute at the centre of a hearing concerning oil development around the islands.

The International Tribunal for the Law of the Sea is considering Argentina’s request for provisional measures concerning the Sea Lion oil project. The tribunal’s published case record identifies the proceedings as a dispute over hydrocarbon exploitation in the South-West Atlantic, with hearings scheduled for November 10 and 11, 2026.

According to the tribunal’s announcement, Argentina submitted its request on October 13 after initiating arbitration against the United Kingdom on September 28. The interim proceedings provide a route to seek protective measures before the separate arbitral tribunal is constituted, rather than a final determination of the underlying claims.

Argentina wants Britain to prevent the commencement or continuation of hydrocarbon exploitation through Sea Lion. Its application also seeks restrictions on new resource permits and the use of exploration information, alongside measures concerning Argentina’s claimed responsibilities to protect the marine environment.

Britain disputes the legal basis for intervention. In its opening presentation, the UK delegation argued that Argentina’s case ultimately depends on a claim to sovereignty over land territory, putting the question beyond the jurisdiction available under the United Nations Convention on the Law of the Sea.

Attorney General Ellie Reeves told the tribunal that restricting the project would undermine the Falkland Islanders’ ability to develop their natural resources. She warned of serious consequences for the islands’ economy and the companies involved, presenting those risks as reasons to reject Argentina’s request rather than as findings accepted by the court.

The competing arguments reflect the longstanding divide over the islands, which Argentina calls the Malvinas. A House of Commons Library briefing describes Argentina’s position as resting on territorial sovereignty, while Britain emphasises the islanders’ right to self-determination and their wish to retain their British status.

The economic stakes extend beyond the immediate legal exchange. The parliamentary briefing identifies Sea Lion, north of the islands, as a prospective source of government revenue and a means of diversifying an economy heavily dependent on fisheries. Those potential benefits help explain Britain’s opposition to restrictions, while Argentina maintains that unilateral development infringes its claimed rights.

The next legal question is whether interim protection is warranted before arbitration proceeds. The tribunal says provisional measures require an initial assessment that the future arbitral tribunal would have jurisdiction and that the situation is urgent. Its consideration of those conditions is distinct from resolving ownership of the islands.