Legal Definitions - intervene

In a legal context, to intervene means for a person or entity who was not originally part of a lawsuit to formally join the case because they have a significant interest in its outcome.

When a lawsuit begins, it typically involves a plaintiff (the party bringing the suit) and a defendant (the party being sued). However, sometimes a third party realizes that the resolution of the case could directly affect their rights, property, or interests. In such situations, this third party can ask the court for permission to join the lawsuit, a process known as intervention. The party seeking to join is called an intervenor.

An intervenor can choose to support either the plaintiff or the defendant, or they can take a position that is adverse to both original parties. Courts generally consider two main types of intervention:

• Intervention as a Right: This occurs when a statute explicitly grants a party the right to intervene, or when the third party's interests are so directly tied to the case that they could be harmed if they are not allowed to participate, especially if their interests are not adequately represented by the existing parties.
• Permissive Intervention: This is at the court's discretion. A court may allow a third party to intervene if their claim or defense shares common legal questions or factual issues with the existing lawsuit, and allowing them to join would not unduly delay the proceedings or unfairly prejudice the original parties.

Here are some examples illustrating how intervention works:

• Example 1 (Environmental Protection): Imagine a state environmental agency sues a large chemical factory for violating pollution regulations. A local community group, whose members live near the factory and have experienced health issues and property damage they attribute to the pollution, files a motion to intervene. The group argues that the agency's primary goal might be regulatory compliance, while their interest is specifically in compensation for damages and stricter long-term environmental safeguards. The court might grant them intervention as a right because their direct health and property interests could be significantly affected by the lawsuit's outcome and might not be fully represented by the state agency.

• Example 2 (Property Dispute): Consider a lawsuit between two distant cousins over the ownership of a valuable family heirloom, such as an antique painting. A third cousin, who was unaware of the dispute, discovers the lawsuit and believes they have a more direct claim to the painting based on a recently found will. This third cousin could file a motion to intervene, arguing that their legal right to the heirloom would be directly determined by the outcome of the existing case, and their interests are clearly not represented by either of the original cousins. This would likely be a case of intervention as a right.

• Example 3 (Consumer Class Action): A group of consumers files a class-action lawsuit against a smartphone manufacturer, alleging a specific battery defect in their latest model. Another group of consumers, who own a slightly older model from the same manufacturer, believes their phones exhibit a similar, though not identical, battery issue. They file a motion for permissive intervention. The court might allow them to join if it finds that their claims share significant common questions of law or fact regarding the manufacturer's design or testing practices, and their inclusion would streamline the litigation without causing undue delay or complexity for the original parties.