What is a requirement for a non-party to intervene in a civil lawsuit?

A non-party seeking to intervene in a civil lawsuit must demonstrate a significant interest in the litigation. This requirement stems from the principle that intervention is intended for individuals or entities that have a stake in the outcome of the case, which may affect their rights or interests. By showing this significant interest, the non-party can claim a right to participate in the proceedings to protect their interests, ensuring that they have an opportunity to present their case and arguments before the court.

In this context, having a significant interest means that the non-party could be directly impacted by the legal decision made in the case. This is contrasted with the incorrect options, which either imply a lack of interest or suggest incorrect procedural requirements, such as filing a new lawsuit or needing an invitation from the plaintiff, which are not necessary conditions for intervention. The focus is on the intervenor's stakes in the matter at hand, thus validating their right to join the case.