Political Reform. Suárez had to risk even more to involve the opposition forces in his plan. In December 1976, the PSOE celebrated its 27th Congress in Madrid, and began to disassociate itself from the demands of the PCE, affirming that it would participate in the next call for elections for the Constituent Cortes. At the beginning of 1977, the year of the elections, Suárez confronted the problem of legalizing the PCE. After the public indignation aroused by the Massacre of Atocha in January 1977 against trade unionists and Communists, Suárez talked with PCE secretary-general Santiago Carrillo in February. Carrillo's willingness to cooperate without prior demands and his offer of a "social pact" for the period after the elections pushed Suárez to take the riskiest step of the transition: the legalization of the PCE in April 1977. However, throughout this critical period the government began a strategy of providing greater institutional space to the (UGT) Socialist union, in comparison to the then Communist-oriented CCOO. The manner in which a unified trade union was strategically countered is an important feature of the Spanish transition, as it limited radical opposition and created the basis for a fractured industrial relations system. Relations of the Suárez government with the Spanish army Adolfo Suárez knew well that the —a group of hard-line Francoists led by José Antonio Girón and Blas Piñar, using the newspapers and as their mouthpieces—had close contacts with officials in the army and exercised influence over important sectors of the military. These forces could constitute an insurmountable obstacle if they brought about military intervention against political reform. To resolve the issue, Suárez intended to support himself with a liberal group within the military, centered on General Díez Alegría. Suárez gave the members of this group the positions of authority with the most responsibility. The most notable personality of this faction within the army was General Manuel Gutiérrez Mellado. However, in July 1976, the Vice President for Defense Affairs was General Fernando de Santiago, a member of a hardline group within the army. De Santiago had shown his restlessness before, during the first amnesty in July 1976. He had opposed the law granting the right to unionize. Suárez dismissed Fernando de Santiago, nominating Gutiérrez Mellado instead. This confrontation with General de Santiago caused a large part of the army to oppose Suárez, opposition that further intensified when the PCE was legalized. Meanwhile, Gutiérrez Mellado