A.R.S. § 12-921: Proceedings involving initiative or referendum measures; standing to intervene; attorney fees or costs

A. In any proceeding in which the constitutionality, legality or application of a law that was enacted through an initiative is at issue, the official initiative proponent, whether an individual, a group of individuals or an organization, that wishes to defend the law shall have the right to intervene as a party and is deemed to have proper standing in the matter.

B. In any proceeding in which the constitutionality, legality or application of a law that was enacted through a referendum is at issue, the legislator who was the first prime sponsor of the referendum and who wishes to defend the law shall have the right to intervene as a party and is deemed to have proper standing in the matter.

C. The only objection that may be raised to a motion to intervene as of right pursuant to this section is that the proposed intervenor does not have a good faith intention to defend the law. Any party or proposed intervenor may raise this objection.

D. A party who intervenes to defend a law pursuant to this section is not liable for attorney fees or costs of any party who is challenging the constitutionality, legality or application of the law.