In 1949 a Constituent Assembly was held in Iran to modify the Persian Constitution of 1906. Shah Mohammad Reza Pahlavi convened the assembly in April; he sought a royal prerogative giving him the right to dismiss the parliament, providing that new elections were held to form a new parliament. He also specified a method for future amendments to the Constitution. The amendments were made in May 1949 by unanimous vote of the Constituent Assembly.
During the previous year, the Shah had been considering changes to the Constitution as part of his various plans to increase the power of the monarchy. He was advised against this action by British and American diplomats who thought it unwise to unbalance the separation of powers. On 4 February 1949, an assassin shot at the Shah, two bullets wounding him. That evening, the government declared martial law and a special session of parliament imposed harsh measures against the Shah's political enemies. The assassin was suspected of being connected to the religious fundamentalist group Fada'iyan-e Islam (Martyrs for Islam, or Devotees of Islam), and loosely associated with the communist-leaning Tudeh Party of Iran. The parliament outlawed the Tudeh Party and had its leaders arrested. The Shah sent pragmatic Ayatollah Abol-Ghasem Kashani to exile—he had formed a strategic alliance with the Fada'iyan. In an atmosphere of national sympathy for the monarchy, the Shah called for a constituent assembly to make amendments to the Constitution, to give him more power. He selected the constituent assembly members from his supporters. He also increased his pressure for the formation of the Senate of Iran, an upper house of parliament that had been written into the constitution in 1906 but never formed. The Senate was expected to favor the Shah.
Background
In 1906 during the drafting of the first Persian Constitution, a bicameral parliament was agreed upon in order to obtain royal approval from Mozaffar ad-Din Shah Qajar. The shah was to appoint half of the 60 members of the upper house, the Senate. The other half of the Senate was to be elected by a two-stage process. The shah expected to be able to control legislation by influencing the Senate. Mozaffar ad-Din Shah Qajar signed the Constitution at the end of December 1906 but died unexpectedly of a heart attack a few days later. Radical politicians and other constitutional delegates did not want a Senate, and after the shah died no action was taken to form one. In mid-1907, the Anjumans of the Mujahidin, a group of workers, artisans and peasants, called for much wider voting rights for men, and they expressed a wish that the Senate never be formed because it would make the nobility more powerful.
The Constitution allowed for a board of ulama (Islamic scholars) who would oversee decisions made by the parliament. The ulama were to be given veto power over legislation. Ayatollah Mirza Sayyed Mohammad Tabatabai was one of those who influenced the composition and adoption of the 1906 Constitution, but he never insisted upon the formation of the board of ulama. Rather, the wishes of the ulama were usually voiced by several members of the Majlis.
Ever since assuming the throne in 1941, the young Shah Mohammad Reza Pahlavi had been working to increase his power. He wanted more weapons and men for the military, which he controlled, and he wanted financial aid from the US. In September 1948, he sent National Bank director Abolhassan Ebtehaj to the US to ask the government of Harry S. Truman for military aid or financial support, and to present the idea that the Shah would activate the Senate. Ebtehaj disclosed the Shah's wish to change the Constitution so that he could dismiss an uncooperative parliament and authorize new elections. The US State Department signaled Ambassador John Cooper Wiley to meet with the Shah to relay Truman's view that the US saw no need for "constitutional reform" since the Shah directed Iran's outward-looking affairs of defense and foreign policy; the US represented that the Shah was not supposed to be in charge of internal politics. This message was affirmed by British Ambassador John Le Rougetel who, seeking stability in Iran's oil industry and continued influence in Iran's parliament, said the UK also advised caution with regard to changes in Iran's constitution. The US State Department prepared a report in January 1949 describing the goal of US diplomacy in Iran as the prevention of any widening of Soviet influence. To that end, the Shah was seen as the most reliable bulwark against Communist aggression in Iran. He was invited to come visit Truman to discuss mutual concerns.