Article 13

A party that intends to challenge an arbitrator shall send notice of its challenge within 15 days after it has been notified of the appointment of the challenged arbitrator, or within 15 days after the circumstances mentioned in articles 11 and 12 became known to that party.

The notice of challenge shall be communicated to all other parties, to the arbitrator who is challenged and to the other arbitrators. The notice of challenge shall state the reasons for the challenge.

When an arbitrator has been challenged by a party, all parties may agree to the challenge. The arbitrator may also, after the challenge, withdraw from his or her office. In neither case does this imply acceptance of the validity of the grounds for the challenge.

If, within 15 days from the date of the notice of challenge, all parties do not agree to the challenge or the challenged arbitrator does not withdraw, the party making the challenge may elect to pursue it. In that case, within 30 days from the date of the notice of challenge, it shall seek a decision on the challenge by the appointing authority.