Section 5. When so requested by any party interested, the commission shall rule upon any question of substantive law properly arising in the course of any proceeding before the commission or any member or members thereof, and any party interested aggrieved by such ruling may object thereto, and may secure a review as hereinafter provided. Any failure or refusal of the commission to rule upon such question at or prior to the entry of a final order or decision shall be taken and recorded as a ruling adverse to the party requesting the ruling. An appeal as to matters of law from any final decision, order or ruling of the commission may be taken to the supreme judicial court by an aggrieved party in interest by the filing of a written petition praying that the order of the commission be modified or set aside in whole or in part.

Such petition for appeal shall be filed with the secretary of the commission within twenty days after the date of service of the decision, order or ruling of the commission, or within such further time as the commission may allow upon request filed prior to the expiration of the twenty days after the date of service of said decision, order or ruling. The commission shall serve such decision, order or ruling upon all parties in interest by mailing, postpaid, within one day of its being entered, and service shall be presumed to have occurred in the normal course of delivery of such mail. Within ten days after such petition has been filed, the appealing party shall enter the appeal in the supreme judicial court sitting in Suffolk county by filing a copy thereof with the clerk of said court, and shall file therewith a certificate that he is of the opinion that there is such probable ground for the appeal as to make it a fit subject for judicial inquiry and that it is not intended for delay; and double costs may be assessed by the court upon any such party whose petition shall appear to the court not to be a fit subject for judicial inquiry or shall appear to be intended for delay.

The record on appeal shall include one copy of the petition of the appellant or other original papers, and of the decision, order or ruling of the commission; and if and to the extent that either the commission or the appellant or any other party to the proceedings so requests within twenty days from filing the petition for appeal with the commission, it shall include one copy of the exhibits and documents introduced in the proceeding before the commission, of the official report of the proceedings and of the findings of fact of the commission. The secretary of the commission shall make an estimate of the expense of the preparation and transmission of the necessary papers and copies of papers aforesaid, and shall give the appellant notice in writing of the amount of such estimate. The appellant, within twenty days after the date of such notice from the secretary, shall pay to him the amount of such estimate and such further amount beyond such estimate as the secretary shall find to be then due for such preparation. The secretary then without delay shall prepare the papers and copies of papers aforesaid for transmission, and when they are ready shall give notice in writing of such fact to the appellant who, within five days after the date of such notice, shall pay to the secretary any balance then due therefor. The record on appeal shall then be certified to the supreme judicial court by the secretary of the commission. The commission or the supreme judicial court or any justice or judge thereof may for cause shown extend the time for doing any of the acts required by this paragraph. The supreme judicial court may order the transmission of the original or a copy of any paper not appearing in the record, or appearing therein in an abbreviated form, if at any time such omitted paper or any omitted part of such abbreviated paper becomes material.

Each claim of appeal shall set forth separately and particularly each error of law asserted to have been made by the commission. Upon the entry of the appeal it shall be heard and determined by the court, which shall have jurisdiction to affirm, modify or set aside such decision, order or ruling of the commission in whole or in part, or remand the proceeding to the commission with instructions subject to review by the full court upon appeal.

Any decision, order or ruling of the commission shall be effective and may be enforced according to its terms and the operation or enforcement thereof shall not be suspended or stayed by the entry of an appeal therefrom. The procedure before the court, except as otherwise set forth herein, shall be that prescribed by its rules, which shall state upon what terms the operation or enforcement of the decision, order or ruling shall be stayed. Any stock, bonds, debentures, convertible debentures, coupon notes, notes or other evidences of indebtedness issued pursuant to and in accordance with a decision, order, or ruling of the commission shall, if issued more than sixty days after the date of service of such decision, order or ruling, be valid and binding in accordance with their terms notwithstanding such decision, order or ruling of the commission is later modified or set aside in whole or in part unless the operation or enforcement of such decision, order or ruling has been suspended or stayed by the court prior to such issuance.

The burden of proof shall be upon the appealing party to show that the decision, order or ruling of the commission appealed from is invalid.

No evidence beyond that contained in the record shall be introduced before the court, except that in cases where issues of confiscation or of constitutional right are involved the court may order such additional evidence as it deems necessary for the determination of such issues to be taken before the commission and to be adduced at the hearing in such manner and upon such terms and conditions as to the court may seem proper. Whenever the court shall order additional evidence to be taken, the commission shall promptly hear and report such evidence to the court so that the proof may be brought as nearly as reasonably possible down to the date of its report thereof to the court. The commission may, after hearing such evidence, modify its findings as to facts and its original decision or orders by reason of the additional evidence so taken, and it shall file with the court such amended decision or orders and such modified or new findings. If the commission shall modify or amend its original decision or orders, the appealing party or any other party aggrieved by such modified or amended decision or order may file with the court, within such time as the court may allow, a specification of any errors of law claimed to have been made by the commission in such modified decision or orders, which specification of errors shall thereupon be considered by the court in addition to the errors of law asserted in the claim of appeal.

Any proceeding in any court in the commonwealth directly affecting an order of the commission, or to which it is a party, shall have preference over all other civil proceedings pending in such court, except election cases.

The supreme judicial court shall also have jurisdiction upon application of the commission to enforce all orders of the commission.