(a) The Attorney General for the District of Columbia shall be given notice of the commencement of any proceeding that this chapter authorizes the Attorney General to bring but that has been commenced by another person.
(b) Whenever any provision of this chapter requires that notice be given to the Attorney General for the District of Columbia before or after commencing a proceeding or permits the Attorney General to commence a proceeding:
(1) If no proceeding has been commenced, the Attorney General may take appropriate action seeking injunctive relief; and
(2) If a proceeding has been commenced by a person other than the Attorney General, the Attorney General, as of right, may intervene in the proceeding.