16.—(1) If the Commission considers that a proposed action plan served on it is not an adequate action plan, the Commission may give notice to P—N.I.
(a)stating its view that the plan is not adequate; and
(b)inviting him to serve on the Commission a revised action plan which is adequate, within such period as may be specified in the notice.
(2) A notice under this paragraph may include recommendations as to action which the Commission considers might be included in an adequate action plan.
(3) If P serves a revised proposed action plan on the Commission in response to a notice under this paragraph, it shall supersede the previous proposed action plan and become final at the end of the prescribed period, unless the Commission has applied for an order under paragraph 17.
(4) If P does not serve a revised action plan in response to a notice under this paragraph, the action plan previously served on the Commission shall become final at the end of the prescribed period, unless the Commission has applied for an order under paragraph 17.