187. A third person who wishes to intervene as a friend of the court during the trial must obtain authorization from the court. The person must file a declaration of intervention setting out the purpose of and grounds for the intervention and notify it to the parties at least five days before the date the application for authorization is to be presented before the court.
After hearing the third person and the parties, the court may grant authorization if it is of the opinion that the intervention is expedient; in making its decision, the court considers the importance of the issues in dispute, particularly in relation to the public interest, and the usefulness of the third person’s contribution to the debate.