(a)     Notwithstanding the preceding provisions of this subchapter or any collective bargaining agreement and subject to subsection (c) of this section, if the head of an agency finds that a particular flexible or compressed schedule under this subchapter has had or would have an adverse agency impact, the agency shall promptly determine not to -

             (1)     establish such schedule; or

             (2)     continue such schedule, if the schedule has already been established.

  (b)     For purposes of this section, "adverse agency impact" means -

             (1)     a reduction of the productivity of the agency;

             (2)     a diminished level of services furnished to the public by the agency; or

             (3)     an increase in the cost of agency operations (other than a reasonable administrative cost relating to the process of establishing a flexible or compressed schedule).

  (c)(1)     This subsection shall apply in the case of any schedule covering employees in a unit represented by an exclusive representative.

       (2)(A)     If an agency and an exclusive representative reach an impasse in collective bargaining with respect to an agency determination under subsection (a)(1) not to establish a flexible or compressed schedule, the impasse shall be presented to the Federal Service Impasses Panel (hereinafter in this section referred to as the "Panel").

             (B)     The Panel shall promptly consider any case presented under subparagraph (A), and shall take final action in favor of the agency's determination if the finding on which it is based is supported by evidence that the schedule is likely to cause an adverse agency impact.

       (3)(A)     If an agency and an exclusive representative have entered into a collective bargaining agreement providing for use of a flexible or compressed schedule under this subchapter and the head of the agency determines under subsection (a)(2) to terminate a flexible or compressed schedule, the agency may reopen the agreement to seek termination of the schedule involved.

            (B)     If the agency and exclusive representative reach an impasse in collective bargaining with respect to terminating such schedule, the impasse shall be presented to the Panel.

            (C)     The Panel shall promptly consider any case presented under subparagraph (B), and shall rule on such impasse not later than 60 days after the date the Panel is presented the impasse.  The Panel shall take final action in favor of the agency's determination to terminate a schedule if the finding on which the determination is based is supported by evidence that the schedule has caused an adverse agency impact.

            (D)     Any such schedule may not be terminated until -

                       (i)     the agreement covering such schedule is renegotiated or expires or terminates pursuant to the terms of that agreement; or

                       (ii)    the date of the Panel's final decision, if an impasse arose in the reopening of the agreement under subparagraph (A) of this paragraph.

  (d)     This section shall not apply with respect to flexible schedules that may be established without regard to the authority provided under this subchapter.