If it appears at any stage of a proceeding in a court in this state that the state is, or is likely to be, interested in the proceeding or that it is a matter of general public interest, the court shall order that a copy of the complaint or petition be served upon the attorney general in the same manner prescribed for serving a summons in a civil action. The attorney general shall intervene in a proceeding when the attorney general determines that the public interest requires it, whether or not the attorney general has been served.