It was brought by Unidos Podemos leader Pablo Iglesias as a result of a corruption case involving high-ranking People's Party (PP) officials, amid accusations of maneuvers from the Rajoy government to influence the judicial system in order to cover-up the scandal.

These parties criticized the motion in that it was aimed more as a propaganda move to meddle in the ongoing PSOE leadership election rather than a genuine and realistic attempt to bring down Rajoy's government.

[1] Furthermore, the ruling People's Party (PP) came under increasing political pressure after a corruption scandal in Murcia had forced the resignation of regional president Pedro Antonio Sánchez.

Operation Lezo resulted in the arrest of former Madrilenian president Ignacio González, who was accused of diverting millions of euros from the public treasury into tax havens and to pay off the regional party's debts during his tenure as Madrid premier.

Several companies—namely OHL, PricewaterhouseCoopers, Indra and Canal de Isabel II, among others—suspect of having illegally financed the PP's Madrilenian branch, had their headquarters in Spain registered by the police in search of incriminating documentation.

[7] Party veteran and former González's boss Esperanza Aguirre resigned from her remaining political offices after seeing many of her former close advisers imprisoned or indicted in a number of judicial procedures.

[10][11][12] In one of the leaked recordings, González pointed to a tape that would allegedly show Rajoy receiving bribes from a businessman, and that this would have been used by Intereconomía CEO Julio Ariza in the past to blackmail him.

[14][15] Secretary of State for Security José Antonio Nieto—Juan Ignacio Zoido's deputy in the interior ministry—came under pressure after being accused of revealing details of the ongoing investigations to González's brother in a private meeting held on 8 March 2017.

[16][17] By mid-May, the string of scandals had splattered Cristina Cifuentes, incumbent president of Madrid, who was accused by the Civil Guard of having been involved in the contract-awarding procedures that led to her party's illegal financing between 2007 and 2012.

[18] By this time, it was also concluded that Esperanza Aguirre had won the 2007 and 2011 regional elections unfairly, with her campaign budgets well above those legally declared, through a system that "hurted political pluralism".

[25] Nonetheless, the Socialists were put in a difficult situation, as opposing the motion would see them rallying behind Rajoy's government amid the ongoing scandals at a time when they were still without a leader.

[39] Iglesias invited the Spanish Socialist Workers' Party (PSOE) into an agreement but acknowledged that the initiative was likely to be defeated, claiming to know that he would not "come out as prime minister from this vote of no confidence, but it is my responsibility",[40] despite the move entailing "enormous risks": while previous motions of no confidence held since the Spanish transition to democracy had also been defeated, the one in 1980 was successful in promoting the figure of Felipe González—said to be one of many contributing factors to his landslide win in the 1982 election—whereas the one in 1987 signaled the twilight of Antonio Hernández Mancha's political career.

[46][47] This same condition was demanded by the Catalan European Democratic Party (PDeCAT), which nonetheless remained more skeptical and argued that they would "evaluate the pros and cons" of supporting the motion before taking a decision.

[58] PP's electoral partners, Navarrese People's Union (UPN) and Asturias Forum (FAC), were widely expected to oppose the motion, whereas Canarian Coalition (CCa) and New Canaries (NCa) hinted at their rejection as well.

[60] A new political scenario arose after Pedro Sánchez's sudden re-election as PSOE leader on 21 May, after he had hinted at registering a future motion of no confidence on Rajoy "if it was to win it" during his leadership election campaign.

[68] It started with a two-hour-long speech by Unidos Podemos spokesperson, Irene Montero, and was followed by a surprise intervention from Prime Minister Mariano Rajoy, who had been widely expected not to participate in the debate himself.