(A) Intervention of Right. On timely application a person has a right to intervene in an action:
(1) when a Michigan statute or court rule confers an unconditional right to intervene;
(2) by stipulation of all the parties; or
(3) when the applicant claims an interest relating to the property or transaction which is the subject of the action and is so situated that the disposition of the action may as a practical matter impair or impede the applicant's ability to protect that interest, unless the applicant's interest is adequately represented by existing parties.
(B) Permissive Intervention. On timely application a person may intervene in an action
(1) when a Michigan statute or court rule confers a conditional right to intervene; or
(2) when an applicant's claim or defense and the main action have a question of law or fact in common.
In exercising its discretion, the court shall consider whether the intervention will unduly delay or prejudice the adjudication of the rights of the original parties.
(C) Procedure. A person seeking to intervene must apply to the court by motion and give notice in writing to all parties under MCR 2.107. The motion must
(1) state the grounds for intervention, and
(2) be accompanied by a pleading stating the claim or defense for which intervention is sought.
(D) Notice to Attorney General. When the validity of a Michigan statute or a rule or regulation included in the Michigan Administrative Code is in question in an action to which the state or an officer or agency of the state is not a party, the court may require that notice be given to the Attorney General, specifying the pertinent statute, rule, or regulation.