After a general election, the appointment of a Prime Minister is the prerogative of the Sovereign.

In appointing a Prime Minister, the Sovereign is guided by constitutional conventions. The main requirement is to find someone who can command the confidence of the House of Commons. This is normally secured by appointing the leader of the party with an overall majority of seats in the Commons, but there could still be exceptional circumstances when The Queen might need to exercise discretion to ensure that her Government is carried on.