Rule 24. Intervention
(a) Intervention of Right. On timely motion, the court must
permit anyone to intervene who:
(1) is given an unconditional right to intervene by
a federal statute; or
(2) claims an interest relating to the property or
transaction that is the subject of the action, and is so situated that
disposing of the action may as
a practical matter impair or impede the movant’s
ability to protect its interest, unless existing parties adequately
represent that interest.
(b) Permissive Intervention.
(1) In General. On timely motion, the court may
permit anyone to intervene who:
(A) is given a conditional right
to intervene by a federal statute; or
(B) has a claim or defense that
shares with the main action a common question of law or fact.
. . .
(3) Delay or Prejudice. In exercising its
discretion, the court must consider whether the intervention will
unduly delay or prejudice the
adjudication of the original parties’ rights.