[11][12][13] The tenure of the newly formed government, which was formally appointed on 13 January 2020, would be quickly overshadowed by the outbreak of the COVID-19 pandemic in March and its political and economical consequences, including the worst worldwide recession since the Great Depression resulting from the massive lockdowns enforced to reduce the spread of SARS-CoV-2.

[14][15] Voting for the Cortes Generales was on the basis of universal suffrage, which comprised all nationals over 18 years of age and in full enjoyment of their political rights.

[18][19] For the Congress of Deputies, 348 seats were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of three percent of valid votes—which included blank ballots—being applied in each constituency.

The prime minister had the prerogative to propose the monarch to dissolve both chambers at any given time—either jointly or separately—and call a snap election, provided that no motion of no confidence was in process, no state of emergency was in force and that dissolution did not occur before one year had elapsed since the previous one.

The Cortes Generales were officially dissolved on 24 September 2019 after the publication of the dissolution decree in the BOE, setting the election date for 10 November and scheduling for both chambers to reconvene on 3 December.

Spanish citizens of age and with the legal capacity to vote could run for election, provided that they were not sentenced to imprisonment by a final court's decision nor convicted by a judgement, even if not yet final, which imposed a penalty of forfeiture of eligibility or of specific disqualification or suspension from public office under specific offences: rebellion, terrorism or other crimes against the state.

Other general causes of ineligibility were imposed on members of the Spanish royal family; the president and members of the Constitutional Court, the General Council of the Judiciary, the Supreme Court, the Council of State, the Court of Auditors and the Economic and Social Council; the Ombudsman; the State's Attorney General; high-ranking members—undersecretaries, secretaries-general, directors-general and chiefs of staff—of Spanish government departments, the Prime Minister's Office, government delegations, the Social Security and other government agencies; heads of diplomatic missions in foreign states or international organizations; judges and public prosecutors in active service; Armed Forces and police corps personnel in active service; members of electoral commissions; the chair of RTVE; the director of the Electoral Register Office; the governor and deputy governor of the Bank of Spain; the chairs of the Official Credit Institute and other official credit institutions; and members of the Nuclear Safety Council; as well as a number of territorial-level officers in the aforementioned government bodies and institutions being barred from running, during their tenure of office, in constituencies within the whole or part of their respective area of jurisdiction.

[34][35] Disqualification provisions for the Cortes Generales extended to any employee of a foreign state and to members of regional governments, as well as the impossibility of running simultaneously as candidate for both the Congress and Senate.

Concurrently, parties, federations or coalitions that had not obtained a mandate in either chamber of the Cortes at the preceding election were required to secure the signature of at least 0.1 percent of electors in the aforementioned constituencies.

This consisted of a special, simplified process, including a shortening of deadlines, electoral campaigning, the lifting of signature requirements if these had been already met for the immediately previous election and the possibility of maintaining lists and coalitions without needing to go through the same pre-election procedures again.

[75] On 24 September, the Spanish Supreme Court ruled in favor of the PSOE's plan to remove the remnants of Francisco Franco from the Valle de los Caídos, a key policy of Pedro Sánchez during the previous legislature.

[76] The prior of the Valle de los Caídos' abbey, Santiago Cantera, initially announced his intention to disregard the Supreme Court's ruling and not authorize Franco's exhumation;[77] however, the Spanish government closed down the monument to the public on 11 October in order to prepare for the exhumation—finally scheduled for 22 October at latest, so for the removal to be over by 25 October—to uphold the Supreme Court's ruling.

[105] In February 2023, Ramón Tamames, a former member of the Communist Party of Spain (PCE), aged 89 at that moment, put himself forward to be an independent candidate for prime minister if a Vox-proposed motion of no confidence were successful.