 The uprising undermined the plans of Polish leader Józef Piłsudski who was planning a coup d'état in Lithuania to replace the Lithuanian government with a pro-Polish cabinet which would agree to a union with Poland (the proposed Międzymorze federation).Because the Sejny Uprising had prompted the Lithuanian intelligence to intensify its investigations of Polish activities in Lithuania, they discovered plans for the coup and prevented it, arresting Polish sympathizers.These hostilities in Sejny further strained the Polish–Lithuanian relations.