Tribunals may accept submissions by non–disputing parties after consulting both parties (Arbitration Rule 37(2)).
A non-disputing party is an individual or entity that is not a party to the dispute, but asks the Tribunal’s permission to file a written submission in the case.
The non-disputing party’s role is to assist the Tribunal in deciding the dispute by providing a perspective different from that of the parties, via the submission of a written brief.
When considering whether to grant the request, the Tribunal takes into account factors such as (Arbitration Rule 37(2)):
Some treaties address the right of non-disputing parties to participate in an arbitration and the criteria applicable to such participation (see e.g. statement of the Free Trade Commission on Non-Disputing Party participation, October 7, 2003).
State parties to a treaty which are not parties to the dispute may have a right under that treaty to make submissions on a question of application or interpretation of the treaty (see e.g. NAFTA article 1128).