Argentina's president has given Britain until about October 12 to suspend the Sea Lion oil project in the North Falkland Basin, or face a case at the International Tribunal for the Law of the Sea.

The Sea Lion development would be the first big oil project in Falklands waters. For Buenos Aires, drilling without its consent violates Argentine sovereignty over islands it calls the Malvinas.

ITLOS is the Hamburg-based court that settles disputes under the UN Convention on the Law of the Sea. Argentina would argue Britain has no right to license resources in disputed waters.

London's position has not moved in decades. Britain says the islanders' right to self-determination is settled, pointing to the 2013 referendum in which 99.8 percent voted to remain British.

Legal experts say an ITLOS case would take years and face jurisdictional hurdles. But the threat alone raises the political and financial risk around the project.

The row is also domestic politics. Standing up to Britain over the islands plays well with Argentine voters whatever the legal outcome.

Sources: thetimes.com, brusselssignal.eu, diplomacyandlaw.com.