of the Union. The constitution of 1964 was adopted ad interim. The Acts of Union themselves included directions on steps to take to elaborate a definitive constitution, to be elaborated by a constituent assembly comprising representatives of both TANU and ASP. This procedure was initiated but was later suspended. Changes in 1965 The Interim Constitution was modified several times after its first layout. A major change was made in 1965 to formalize the one-party nature of the Tanzanian government. Coherent to the double government structure defined in 1964, the 1965 Constitution identified two government parties, TANU for the Union and ASP for Zanzibar. In the following years, several amendments were added. Those reduced the autonomy of Zanzibar and further strengthened the one-party state. For example, an amendment in 1975 established that all the government institutions, including the Parliament, were subordinate to the party's executive committee. At that time, TANU and ASP were about to merge into the Chama Cha Mapinduzi (CCM), something that happened in 1977. The Constitution of the United Republic of Tanzania as further Amended (Fourth) Constitution (1977-today One month after CCM was founded, the Permanent Constitution was approved. This Constitution essentially confirmed the main principles of the Republic and Interim Constitutions, i.e., strong presidency, dual government structure, one-party state. Since 1977, several amendments have been applied to the original Constitution. Many of these are related to the relationship between the united government and the Zanzibar government. In the early 1990s, President of the Union Ali Hassan Mwinyi launched a program of liberal reforms. He nominated a commission (named Nyalali Commission after its president Francis Nyalali) dedicated to preparing the transition to a multi-party political system. Based on the commission's works, several amendments were promulgated. The Eighth Amendment (1992) established that a member of any registered political party could run for any political seat; coherently, new rules were defined governing the parties' registration. The Ninth Amendment reorganized presidential elections and introduced the possibility of impeachment by the Parliament; further, it separated the functions of President and Prime Minister. The relationships between Zanzibar and the Union were also modified over time. For example, the Eleventh Amendment established the President of Zanzibar and the Union vice president as two different, independent roles. April 2000: The Thirteenth Constitutional Amendment It introduced the following changes: - Prior, a candidate needed 50% of votes in presidential elections to be declared president of the