Thursday, May 24
The Cabildo interpreted the decision of the open cabildo in its own way. When it formed the new Junta to govern until the arrival of representatives from other cities, Leiva arranged for former viceroy Cisneros to be appointed president of the Junta and commander of the armed forces. There are many interpretations of his motives for departing from the decision of the open cabildo in this way. Four other members were appointed to the Junta: criollos Cornelio Saavedra and Juan José Castelli, and peninsulars Juan Nepomuceno Solá and José Santos Inchaurregui.
Leiva wrote a constitutional code to regulate the actions of the Junta. It stipulated that the Junta could not exercise judicial power, which was reserved for the Royal Audiencia of Buenos Aires; that Cisneros could not act without the support of the other members of the Junta; that the Cabildo could dismiss anyone who neglected his duty; that the Cabildo's consent would be required to create new taxes; that the Junta would sanction a general amnesty for those who had aired opinions at the open cabildo; and that the Junta would invite the other cities to send delegates. The commanders of the armed forces, including Saavedra and Pedro Andrés García, agreed to this code. The Junta swore the oath of office that afternoon.
These developments shocked the revolutionaries. Unsure of what to do next, they feared that they would be punished, like the revolutionaries of Chuquisaca and La Paz. Moreno abjured relations with the others and shut himself in his home. There was a meeting at Rodríguez Peña's house. They felt that the Cabildo would not pursue such a plot without the blessing of Saavedra and that Castelli should resign from the Junta. Tagle took a different view: he thought that Saavedra may have accepted out of weakness or naivety and that Castelli should stay in the Junta to counter the others' influence on him. Meanwhile, a mob led by Domingo French and Antonio Beruti filled the Plaza. The stability of Cisneros in power, albeit in an office other than Viceroy, was seen as an insult to the will of the open cabildo. Colonel Martín Rodriguez warned that, if the army were to commit support to a government that kept Cisneros, they would soon have to fire on the people, and that they would revolt. He said that "everyone without exception" demanded the removal of Cisneros.
That night, Castelli and Saavedra informed Cisneros of their resignation from the newly formed Junta. They explained that the population was on the verge of violent revolution and would remove Cisneros by force if he did not resign as well. They warned that they did not have the power to stop that: neither Castelli to stop his friends, nor Saavedra to prevent the Regiment of Patricians from mutiny. Cisneros wanted to wait for the following day, but they said that there was no time for further delays, so he finally agreed to resign. He sent a resignation letter to the Cabildo for consideration on the following day. Chiclana felt encouraged when Saavedra resigned, and started to request signatures for a manifesto about the will of the people. Moreno refused any further involvement, but Castelli and Peña trusted that he would eventually join them if events unfolded as they expected.