Under what circumstances can a nonparty intervene in an action as a matter of right?

A nonparty can intervene in an action as a matter of right primarily when they have an unconditional right under a federal statute or when they have a significant interest that could be adversely affected by the outcome of the litigation. This aligns with the principles set forth in Rule 24 of the Federal Rules of Civil Procedure, which provides for intervention of right.

In terms of an unconditional right under a federal statute, the law may explicitly grant certain individuals or entities the ability to intervene in cases that affect them directly or significantly. Furthermore, when a nonparty possesses a significant interest in the subject matter of the litigation, they may be entitled to intervene to protect that interest. For instance, if a party's legal rights may be diminished by the outcome of a case, they have the grounds to intervene.

The other options do not reflect the legal standards for intervention as a matter of right. Inviting a nonparty to intervene is not a requirement; intervention can occur regardless of any invitation. Having legal representation is not a prerequisite for intervention; the focus is on the interest at stake, not the presence of counsel. Additionally, being a witness does not inherently grant a right to intervene; a witness may have relevant information, but that alone does not establish the necessary legal interest