Floor Crossing

Explanation

Floor crossing (also called "crossing the aisle" or "crossing the floor") occurs when a legislator votes against their party's position or formally switches parties while retaining their seat. In Westminster systems, this is considered a serious breach of party discipline. Some countries ban floor crossing entirely — South Africa's constitution originally did so, then allowed it in specific windows. Floor crossing can destabilize governments in parliamentary systems where the ruling coalition depends on a precise majority. High-profile defections can trigger confidence votes, leadership challenges, or realignments within legislatures.