Luis Barceló, the communist commander of I Corps, appointed himself commander of the Army of the Centre and the leader of forces opposing the Council. After setting up his command post in the Pardo Palace, he sent his men to Casado’s headquarters near the airfield of Barajas, where they arrested members of his staff, brought them back to El Pardo and executed them on Barceló’s orders. Meanwhile, the troops led by Ascanio reached the heart of Madrid, where they came up against the anarchists of the 70th Division and
Once peace was restored to the streets of Madrid on 12 March, the Council of National Defence met to prepare peace negotiations and organize the evacuation of the republican army. In the note sent to Franco, they explained that they had not been able to get in touch while crushing the revolt and restoring order. They wished to establish conditions for laying down arms and ending the war. But once again the insistence on national independence and the idea that Casado might have saved the country from communism was bound to irritate Franco deeply. They asked for no reprisals of any form against civilians or soldiers and a period of 25 days to allow anyone who wanted to leave Spain to do so. Casado and Matallana were appointed negotiators.
On the next day, 13 March, Casado summoned Lieutenant-Colonel Centaño and entrusted him with the conditions to be passed to Franco. Six days later Franco replied in cutting and glacial terms: ‘Unconditional surrender incompatible with negotiations and presence in nationalist zone of senior enemy commanders.’33
Centaño advised Casado to appoint two other officers, and the Council decided to send to Burgos Lieutenant-Colonel Antonio Garijo and Major Leopoldo Ortega. Despite the cold reception of his earlier message, Casado drew up another document addressed to the nationalists in which he emphasized the dangers they had run in taking on the communists and the risks they faced if they confounded the hopes which ‘everyone has placed in this Council’.On 21 March, agents of the SIPM informed Casado that the nationalist supreme command had agreed to the visit of Garijo and Ortega to Burgos two days later. The two officers went and were told that on 25 March the whole of the republican air force must be surrendered, and two days later the republican army must raise the white flag in unconditional surrender. When this was known, some republican commanders, feeling angered and humiliated, considered fighting on, but it was too late to reverse the emotional process of surrender. Casado, meanwhile, sent another letter to Franco, but it too was doomed to failure.
When 25 March arrived, bad weather and the problem of unserviceable aircraft made it impossible to hand over the air force. The two republican emissaries went back to explain the situation, but their nationalist intermediaries were ordered by Franco’s headquarters to send them away. Instructions for the final offensive were issued to nationalist commanders immediately.