Rule 21 2

Upon timely application, anyone may be permitted to intervene in an action:(a) When a statute confers a conditional right to intervene; or(b) when an applicant’s claim or defense and the main action have a question of law or fact in common.When a party to an action relies for ground of claim or defense upon any statute or executive order administered by a governmental officer or agency or upon any regulation, order, requirement or agreement issued or made pursuant to the statute or executive order, the officer or agency upon timely application may be permitted to intervene in the action. 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.