Unity of Interest Law and Legal Definition

Unity of interest means that the interest of the parties in the subject-matter is such that they stand or fall together and that judgment against one will similarly affect the other.

Following is an example of a state statute defining the term unity of interest. Where the court determines a unity of interest exists, several plaintiffs or several defendants may be considered as a single party for the purpose of making challenges, or the court may allow additional peremptory challenges and permit them to be exercised separately or jointly. For the purposes of this section, a unity of interest means “that the interests of the several plaintiffs or of the several defendants are substantially similar.” A unity of interest shall be found to exist among parties who are represented by the same attorney or law firm. In addition, there shall be a presumption that a unity of interest exists among parties where no cross claims or apportionment complaints have been filed against one another. [Conn. Gen. Stat. § 51-241].