The appeal is from an order of the District Court denying a motion of appellant, plaintiff in the District Court, for a mandatory preliminary injunction to1 require appellees, defendants in the District Court, to comply with an arbitration award alleged by appellant to require appellees to enter into a collective bargaining agreement with appellant.

Resolution of the issues raised by the complaint in the District Court, and of the motion there for a preliminary injunction, will in part at least be affected by a proceeding instituted by appellant against appellees before the National Labor Relations Board. The proceeding has gone to hearing and is still pending before the Board. For this reason, as well as because of uncertainties in other respects as to< the facts essential to sus *743 tain its right to the preliminary in junetion we are not in a position to direct the District Court to grant appellant that relief.

Affirmed.