The idiomatic sense is derived from early rules of the Sejm that gave each nobleman who was a member a veto.
- The Sejm of the Republic of Poland.
- (idiomatic) A deliberative body institutionally unable to reach a decision.
1966, Raymond Aron, Peace and war: a theory of international relations:
- But the conversation produced no result. In a summit conference the nay-saver is in a position to prevent what his allies desire. An alliance among democratic nations is a Polish parliament in which the liberum veto functions (within certain limits).