A person or entity who is not a party to a lawsuit generally may intervene in the lawsuit and become a party to it by filing a plea in intervention prior to the entry of the court’s judgment—provided the court does not reject (strike) the intervention. An intervenor is not required to secure the court’s permission to intervene, and the party who opposed the intervention has the burden to challenge it by filing a motion to strike.
A person or entity has a right to intervene if the intervenor could have brought the same lawsuit, or any part of it in his own name—or, if the action had been brought against him, he would be able to defeat the lawsuit, or some part of it.
A trial court abuses its discretion by striking an intervention if (1) the intervenor meets the above test, (2) the intervention will not complicate the case by an excessive multiplication of the issues, and (3) the intervention is almost essential to effectively protect the intervenor’s interest.
In Texas, a person or entity not originally part of a lawsuit can intervene in the case by filing a plea in intervention before the court renders a judgment. This process does not require the court's permission, and the burden to challenge the intervention lies with the party opposing it. To have the right to intervene, the potential intervenor must show that they could have initiated the same lawsuit or a part of it, or if the lawsuit had been brought against them, they would have the ability to defeat it, wholly or partially. The court should not strike down an intervention if the intervenor passes this test, the intervention does not overly complicate the case by adding too many issues, and the intervention is nearly essential for protecting the intervenor's interests. Striking an intervention under these circumstances could be considered an abuse of discretion by the trial court.
