Once a
general election has been called by the
monarch, political parties designate their candidates to stand for prime minister—usually the party leader. A prime minister is dismissed from office the day after the election, but remains in office as a caretaker until his/her successor is sworn in. after the
general election in July 2023, conforming the
15th Parliament after the restoration of democracy in 1977. Following the general election and other circumstances provided for in the Constitution, the sovereign meets with the leaders of the
parties represented in the Congress of Deputies, and then consults with the
Speaker of the Congress of Deputies () as representative of the whole of parliament), before nominating a candidate for the prime ministership. This process is spelled out in Section 99 of the Constitution. is the official residence and workplace of the prime minister. By
political custom, the sovereign's nominees have usually been from parties who have a
plurality of seats in the Congress (i.e. the largest party). Although there is no legal requirement for this, it is seen as a royal endorsement of the democratic process—a fundamental concept enshrined in the 1978 Constitution. The largest party can end up not ruling if rival parties form a
coalition—as happened in 2018 with the election of PSOE leader
Pedro Sánchez. More commonly, if neither of the two major parties (
Spanish Socialist Workers' Party or
People's Party) are able to command an absolute majority of the Congress by themselves, one will rule as a minority by adopting some aspects of the minor party platforms in an effort to attract them into parliamentary agreements to vote in the major party's favour, or at least abstain. The monarch's order nominating a prime ministerial candidate is countersigned by the Speaker of the Congress, who then presents the nominee before the Congress of Deputies in a process known as a
parliamentary investiture (
Investidura parlamentaria). During the investiture proceedings, the candidate describes their
political agenda in an
Investiture Speech to be debated and submitted for a
vote of confidence (
Cuestión de confianza) by the Congress, effecting an
indirect election of the head of government. Confidence is awarded if the candidate receives a majority of votes in the first poll (currently 176 out of 350 MPs), but if the confidence is not granted, a second vote is scheduled forty-eight hours later in which a simple majority of votes cast (i.e., more "yes" than "no" votes) is required.). After the nominee is confirmed, the Speaker of the Congress formally reports the fact to the sovereign. The monarch then appoints the candidate as the new prime minister and this too is countersigned by the Speaker.—next to a
Bible and a
crucifix. The prime minister must take the oath or affirmation placing the right hand on the Constitution. Currently, only one prime minister has refused to take the oath of office next to religious symbols:
Pedro Sánchez, along with most of his Cabinet members. His predecessor,
Mariano Rajoy, a Catholic, put his right hand on the Constitution and, at the same time, his left hand on the Bible. As per tradition, government officials can choose to take the oath using "prometo, por mi conciencia y honor" ("I promise, under my conscience and honor") or simply using "I swear", which is more formal and linked to religion. The oath as taken by Prime Minister Zapatero on his first term in office on 17 April 2004 was: Once appointed, the prime minister forms his government whose ministers are appointed and removed by the monarch on the prime minister's advice. In the political life of Spain, the monarch would already be familiar with the various political leaders in a professional capacity, and perhaps less formally in a more social capacity, facilitating their meeting following a general election. Conversely, nominating the party leader whose party maintains a plurality and who are already familiar with their party
manifesto facilitates a smoother nomination process. In the event of
coalitions, the political leaders would customarily have met beforehand to hammer out a coalition agreement before their meeting with the Sovereign. ==Constitutional authority==