(a) General policy. The Commission will not review interlocutory rulings of a presiding officer except in extraordinary circumstances.

(b) Appeals certified by the presiding officer. (1) Rulings of the presiding officer may be appealed to the Commission when the presiding officer certifies in writing that an interlocutory appeal is warranted. The presiding officer shall not certify an appeal unless the officer finds that:

(i) The ruling involves an important question of law or policy concerning which there is substantial ground for difference of opinion; and

(ii) An immediate appeal from the ruling will materially advance the ultimate termination of the proceeding or subsequent review will be an inadequate remedy.

(2) A request for the presiding officer to certify an appeal shall be made by motion within five days after the presiding officer's ruling has been issued. The request shall set forth with specificity the reasons that a participant believes that an appeal meets the criteria of paragraphs (b)(1)(i) and (ii) of this section. Such requests shall also state in detail the legal, policy, and factual arguments supporting the participant's position that the ruling should be modified. If the appeal is from a ruling rejecting or excluding evidence, such request shall include a statement of the substance of the evidence which the participant contends would be adduced by the excluded evidence and the conclusions intended to be derived therefrom.

(3) The presiding officer may request responsive pleadings from other participants prior to ruling upon the request to certify an appeal to the Commission.

(c) Appeals not certified by the presiding officer. A participant may request Commission review of a presiding officer's decision denying certification of an appeal by motion within five days of the decision. If the presiding officer fails to act on a request for certification within 15 days of the issuance of the ruling in question, the participant seeking certification may apply for review by the Commission within 20 days of the ruling in question. Unless the Commission directs otherwise, its review of the application for review will be based on the record and pleadings filed before the presiding officer pursuant to paragraph (b) of this section.

(d) Action by the Commission. (1) The Commission may dismiss an appeal certified by the presiding officer if it determines that:

(i) The objection to the ruling should be deferred until the Commission's consideration of the entire proceeding; or

(ii) Interlocutory review is otherwise not warranted or appropriate under the circumstances.

(2) When the presiding officer declines to certify an appeal, the Commission will not permit an interlocutory appeal unless it determines:

(i) That the presiding officer should have certified the matter;

(ii) That extraordinary circumstances exist; and

(iii) That prompt Commission decision is necessary to prevent grave detriment to the public interest.

(3) If the Commission fails to issue an order permitting an interlocutory appeal within 15 days after the presiding officer certifies the appeal or a participant files an application for review, the appeal shall be deemed denied. If the Commission issues an order permitting an appeal, it may rule upon the merits of the appeal in that order or at a later time.

(e) Effect of appeals. Unless the presiding officer or the Commission so orders, the certification of an appeal or the filing of an application for review shall not stay the proceeding or the effectiveness of any ruling.

(f) Review at conclusion of proceeding. If the Commission does not entertain an interlocutory appeal of a presiding officer's ruling, objection to the ruling may be raised:

(1) In briefs to the presiding officer or the Commission at the conclusion of hearings on the record; or

(2) By the deadline for submission of comments or reply comments, whichever is later, in all other proceedings in which a hearing on the record is not held.