Article 15.3
The Race Director shall have overriding authority in the following matters and the clerk of the course may give orders in respect of them only with his express agreement:
a) The control of practice and the race, adherence to the timetable and, if he deems it necessary, the making of any proposal to the stewards to modify the timetable in accordance with the Code or Sporting Regulations.
b) The stopping of any car in accordance with the Code or Sporting Regulations.
c) The stopping of practice or suspension of the race in accordance with the Sporting Regulations if he deems it unsafe to continue and ensuring that the correct restart procedure is carried out.
d) The starting procedure.
e) The use of the safety car.
This rule will probably mean any Merc appeals are batted away both internally and at CAS.