39 Miss. Code. R. 1-6-121
Upon timely motion, any person may be permitted to intervene in a proceeding when the movant has a substantial interest relating to the property, transaction or outcome of the proceeding at issue and the movant is so situated that the disposition of the proceeding may as a practical matter impair or impede his or her ability to protect that interest. Leave thus granted shall entitle the intervenor to the status of a party and to participate as a party, subject to such conditions as may be prescribed by the Commission.
A person desiring to intervene shall file a motion to intervene with the Commission, shall serve a motion to intervene upon the filing party and upon all other parties in the proceeding. The motion shall state the grounds and specific facts therefore. The motion shall be signed by the attorney appearing on behalf of a party or by the party himself and shall provide the movant's name, address, facsimile number and e-mail address, where available. The motion shall contain a certificate of service stating that service was made upon all parties of record. The movant shall attach a proposed order to the motion filed with the Commission.
Motions to intervene shall be filed on or before twenty (20) days from the date the proposed intervenor receives actual notice or constructive notice of the proceeding, whichever occurs first. Constructive notice is given by the filing of a proceeding; however, if public notice thereof is published, then constructive notice is given by the last publication date.
Any utility or party may file an objection to the intervention request within seven (7) calendar days of the filing of an intervention request. If no objection is timely filed and the Commission deems it proper, the Commission may enter an order allowing the timely intervention.
Motions to intervene not timely filed under this rule shall be allowed at the discretion of the Commission and only upon good cause shown. Except as otherwise ordered, a grant of an untimely motion to intervene must not be a basis for delaying or deferring any procedural schedule established prior to the grant of that motion. The Commission may impose limitations on the participation of a late intervenor to avoid delay and prejudice to the other participants. Except as otherwise ordered, a late intervenor must accept the record of the proceedings as the record was developed prior to the late intervention.
The Commission may, in any proceeding pending before it, order that any person or corporation whose interest will be affected by the result of such proceeding be made or permitted to be made a party thereto. Thereafter, all those so made parties, or those permitted to be so made parties who avail themselves of such right, shall be entitled to have notice of hearings and be heard in person or by attorney, subject to such conditions as may be prescribed by the Commission in each case.
A public witness does not have the rights of a party to examine witnesses or otherwise participate in the proceedings. The Commission, in any proceeding before it, may allow public witnesses to introduce evidence at a hearing by written or oral statements and exhibits. A public witness's written or oral statements and exhibits may be subject to examination and objection.
The person who initiated the filing shall upon written request provide the requesting intervenor with copies of documents previously filed by the party.
39 Miss. Code. R. 1-6-121