(Basque: EAJ, Euzko Alderdi Jeltzalea; Spanish: PNV, Partido Nacionalista Vasco) and the Democratic Pact for Catalonia (PDC, Pacte Democrátic per Catalunya) in their respective regions, nationalist parties also began to show their political strength in these elections. The Constituent Cortes (elected Spanish parliament) then began to draft a constitution, in the middle of 1977. In 1978, the Moncloa Pact was passed: an agreement amongst politicians, political parties, and trade unions to plan how to operate the economy, during the transition. The Spanish Constitution of 1978 went on to be approved in a referendum, on 6 December 1978. Governments of the UCD Prime Minister Adolfo Suárez's party, the UCD, received a plurality, but not an absolute majority, in both the June 1977 and March 1979 elections. To exercise power, the UCD had to form parliamentary coalitions with other political parties. From 1979, the government spent much of its time working to hold together the many factions within the party itself, as well as their coalitions. In 1980, the Suárez government had, for the most part, accomplished its goal of a transition to democracy and lacked a further clear agenda. Many UCD members were fairly conservative and did not want further change. For example, a bill to legalize divorce caused much dissension inside the UCD, in spite of being supported by the majority of the populace. The UCD coalition fell apart. The clashes among the several factions, inside the party, eroded Suárez's authority and his role as leader. The tension exploded in 1981: Suárez resigned as the head of government, and Leopoldo Calvo Sotelo was appointed, first to lead the new cabinet, and later, to the presidency of the UCD; social democrats led by Francisco Fernández Ordóñez defected from the coalition, later joining the PSOE, while Christian democrats left to form the People's Democratic Party. While the democratic normalization had succeeded in convincing ETA (pm), the "political-military" faction of ETA, to abandon arms and enter parliamentary politics, it did not stop the continuation of terrorist attacks by ETA (m) ("ETA Military"; later simply "ETA") or to a lesser extent, GRAPO. Meanwhile, restlessness in various sections of the armed forces created fear of an impending military coup. Reactionary elements in the army attempted a coup known as 23-F, in which Lieutenant Colonel Antonio Tejero led an occupation by a group of Guardia Civil of the Congress of Deputies, on the afternoon of 23