Irdc.ir: The 22 February 1921 British coup, transfered the power to an officer called Reza Khan Mirpanj. This was an opening to Iran's new era and put the constitutional parliament in the hands of military forces, and until August 1941, when Iran was occupied by the Allies and Reza Shah was exiled to Mouris Islands, there were no arguments and discussions in the parliament, and the members only obeyed what they were told. Reza Khan started the process of becoming the king from the parliament, when he was the minister of war. From the fourth parliament to the thirteenth one (exile of Reza Khan to South Africa) , the elections and the parliament was nothing but a masquerade where every one pretented to work for the people by the laws of onstitution, but in fact they were doing what Reza Khan was asked them. He entered his men into the parliament to eventually gain enough power to overthrow Qajars. In the time of the election for the fourth parliament, it has only been three months from the coup, and Reza Khan could not have had the power to manipulate the election, but with the cooperation of some members, made his way into the fifth election. In the fall of 1923, he formed a special committee in Tehran under the authority of Khodayar Khan, a military general which became the minister of war later, to control the election, and sent their chosen members to the parliament.
In some cases, Reza Khan himself used threatening and other ways to make military commanders and heads of tribes to chose specific individuals for the parliament. In the fifth parliament, just a few members where chosen against the will of the military and Reza Khan. But in Tehran the military government could not interfer in the process of election. Qavam-al-Saltaneh could not enter the parliament because he was exiled. Sheikh Ali Modarres, the famous scholar attended the meetings and was the leader of the minorities in the parliament, but he was prevented from entering the parliament of the founders.
The British ambassador mentions in a report from 1926 that the parliament of Iran can't be taken seriously, because there is not a free election and the members are not independant.
Despite all the efforts of Reza khan, some independant members entered the parliament, especially from Tehran, and by the leadership of Seyyed Hassan Tadayyon, stood against Reza Khan.
The first conflict between majorities and minorities of the parliament was about the credentials. Modarres and his men disapproved the credentials of other members and called them and the way they were chosen "non national" and as the result of force and tyranny. The next conflict was about the republicanism. This had happened after Sardar Sepah was chosen as the head of the ministers and claimed to be the president after overthrowing Qajars. The long discussions and conflicts ended up with Modarres being slapped on his face and with opposition of the scholars and people from Bazaar. Reza Khan traveled to Qom, negotiated with scholars and announced that he would not persume his claim of republicanism.
But this was not an end to the thought of overthrowing Qajars. In a year, his supporters gathered as the parliament of the founders and approved the single article to take authority from Shah and chose Reza Khan as the new King. With him in charge, the manipulation in election became a routine until the thirteenth parliament.
Source: Political Studies and Research institution