29 U.S.C. § 179
Whenever a district court has issued an order under section 178 of this title enjoining acts or practices which imperil or threaten to imperil the national health or safety, it shall be the duty of the parties to the labor dispute giving rise to such order to make every effort to adjust and settle their differences, with the assistance of the Service created by this chapter. Neither party shall be under any duty to accept, in whole or in part, any proposal of settlement made by the Service.
Upon the issuance of such order, the President shall reconvene the board of inquiry which has previously reported with respect to the dispute. At the end of a sixty-day period (unless the dispute has been settled by that time), the board of inquiry shall report to the President the current position of the parties and the efforts which have been made for settlement, and shall include a statement by each party of its position and a statement of the employer's last offer of settlement. The President shall make such report available to the public. The National Labor Relations Board, within the succeeding fifteen days, shall take a secret ballot of the employees of each employer involved in the dispute on the question of whether they wish to accept the final offer of settlement made by their employer as stated by him and shall certify the results thereof to the Attorney General within five days thereafter.
29 U.S.C. § 179