Lis alibi pendens

The principle of lis alibi pendens (Latin for "dispute elsewhere pending") applies both in municipal law, public international law, and private international law to address the problem of potentially contradictory judgments. If two courts were to hear the same dispute, it is possible they would reach inconsistent decisions. To avoid the problem, there are two rules.

Res judicata provides that once a case has been determined, it produces a judgment either inter partes or in rem depending on the subject matter of the dispute, i.e. although there can be an appeal on the merits, neither party can recommence proceedings on the same set of facts in another court. If this rule were not in place, litigation might never come to an end.

The second rule is that proceedings on the same facts cannot be commenced in a second court if the lis i.e. action, is already pendens, i.e. pending, in another court. Lis alibi pendens arises from international comity and it permits a court to refuse to exercise jurisdiction when there is parallel litigation pending in another jurisdiction. Shany (2003) considers the problem within the public international law field where, for example, the Southern Bluefin Tuna dispute could have been determined either by the International Court of Justice (ICJ), or by tribunals established under the United Nations Convention on the Law of the Sea (UNCLOS), and the Swordfish dispute, which was submitted simultaneously to both the International Tribunal for the Law of the Sea (ITLOS) and a dispute settlement panel of the World Trade Organisation (WTO). Kwak and Marceau (2002) consider the jurisdiction between the dispute settlement mechanisms of regional trade agreements (RTAs) and that of the WTO.

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