a) For the purposes of this Part, a person who intervenes in a pending docket in which the existing parties have already requested mediation shall be able to participate in the mediation. If such intervening party chooses not to participate in the mediation, the mediation may proceed without the intervening party. If the mediation concludes successfully, any resulting agreement brought into the pending docket shall be treated as a settlement proposal offered by the mediation participants and, if rejected by any party, shall be treated as a contested matter in the pending docket as provided in Commission rules (see 83 Ill. Adm. Code 200).

1. b) An intervening party that chooses to participate in the mediation may raise new issues for mediation with the consent of all other then-existing mediation participants.
2. c) An intervening party shall not have the right to request that the appointed mediator be replaced by another mediator, where the intervening party has not initiated the mediation.