(a) Where there appears to have been a substantial change in operative fact or relevant law, or where it appears there may have been a misinterpretation of fact or mistake in the law, an objection may be reconsidered, if it is deemed appropriate, at the instance of the Attorney General.

(b) Notice of such a decision to reconsider shall be given to the submitting authority, to any party who commented on the submission or requested notice of the Attorney General's action thereon, and to interested parties registered under § 51.32, and the Attorney General shall decide whether to withdraw or to continue the objection only after such persons have had a reasonable opportunity to comment.