The board shall except where an employe of the Commonwealth is involved have power to petition the court of common pleas of any county wherein the unfair practice in question occurred, or wherein any person charged with the commission of any unfair practice resides or transacts business, for the enforcement of such order and for appropriate temporary relief or restraining order, and shall certify and file in the court a transcript of the entire record in the proceeding, including the pleadings and testimony upon which such order was entered and the findings and order of the board. In the instance of the exception involving the said Commonwealth employes, the board shall file its petition in the Commonwealth Court. Upon such filing, the court shall cause notice thereof to be served upon such person, and thereupon shall have jurisdiction of the proceeding and of the question determined therein, and shall have power to grant such temporary relief, restraining or mandamus order as it deems just and proper or requisite to effectuate the policies of this act and to make and enter upon the pleadings, testimony, and proceedings set forth in such transcript a decree enforcing, modifying and enforcing as so modified, or setting aside, in whole or in part, the order of the board. The parties before the court shall be the board, the person charged with the commission of any unfair labor practice, and may include the charging party. No objection that has not been urged before the board, its members or agents shall be considered by the court unless the failure or neglect to urge such objection shall be excused because of extraordinary circumstances. The findings of the board as to the facts, if supported by substantial and legally credible evidence, shall be conclusive. If either party shall apply to the court for leave to adduce additional evidence, and shall show to the satisfaction of the court, that such additional evidence is material, and that there were reasonable grounds for the failure to adduce such evidence at the hearing before the board, its members or agent, the court may order such additional evidence to be taken before the board, its members or agent, and to be made a part of the transcript. The board may modify its findings as to the facts or make new findings by reason of additional evidence so taken and filed, and it shall file such modified or new findings which, if supported by substantial and legally credible evidence, shall be conclusive, and shall file its recommendations, if any, for the modification or setting aside of its original order. The jurisdiction of the court of common pleas, or the Commonwealth Court, as the case may be, shall be exclusive within the limits of its jurisdiction.