The term used when a member of a legislature leaves his party on whose ticket he was elected to join the ruling party or the opposition, is called

The term used when a member of a legislature leaves his party on whose ticket he was elected to join the ruling party or the opposition, is called floor crossing. In politics, a politician is said to cross the floor if they change their party allegiance. Crossing the floor may mean changing to second party after being elected as a member of a first party, or voting against the approved party lines.