In a parliamentary system, the prime minister sets the national agenda, appoints cabinet officials, and governs at the behest of a party or a coalition of parties. In parliamentary systems, presidents—if they exist—serve as largely ceremonial heads of state. In constitutional monarchies, such roles are filled by the king or queen. If a prime minister loses the legislative mandate, opposition parties may call for a vote of confidence in an effort to topple the sitting government. In this event, the president may be called upon to formally dismiss the legislature and schedule fresh elections.
