The liberum veto (Latin for "free veto") was a parliamentary device in the Polish–Lithuanian Commonwealth. It was a form of unanimity voting rule that allowed any member of the Sejm (legislature) to force an immediate end to the current session and to nullify any legislation that had already been passed at the session by shouting either Sisto activitatem! (Latin: "I stop the activity!") or Nie pozwalam! (Polish: "I do not allow!"). The rule was in place from the mid-17th century to the late 18th century in the Sejm's parliamentary deliberations. It was based on the premise that since all Polish noblemen were equal, every measure that came before the Sejm had to be passed unanimously. The liberum veto was a key part of the political system of the Commonwealth, strengthening democratic eleme