Argentina has told an international tribunal that Britain’s approval of oil drilling off the Falkland Islands has dramatically deepened a sovereignty dispute that led to war four decades ago.

At the start of an historic legal clash at the Hamburg-based International Tribunal for the Law of the Sea (Itlos), an Argentinian legal team argued that the oil project must be suspended.

Javier Oyarzábal, chief legal adviser to Argentina’s ministry of foreign affairs, said that the 3,400 inhabitants of the Falkland Islands, whose status as a British overseas territory is disputed by Buenos Aires, had no right to the resources around the south Atlantic archipelago.

Oyarzábal said: “[Argentina] respects the interests of the inhabitants of the islands and their way of life as enshrined in the Argentine constitution … What these British citizens do not have is a right to decide to which state the islands belong …

“These resources belong to the Argentine people.…