All candidates to the Assembly of Experts must be approved by the Guardian Council whose members are, in turn, appointed either directly or indirectly by the Supreme Leader.

[9][10] As the 3 August 1979 elections for the Assembly of Experts drew near, Ruhollah Khomeini began to signal to Iranians which candidates they should support and which they should avoid.

According to the Constitution, the criteria of qualification for the office of the Supreme Leader include "Islamic scholarship, justice, piety, right political and social perspicacity, prudence, courage, administrative facilities and adequate capability for leadership.

"[13] The jurist deemed as the most well-versed in Islamic regulations, in fiqh, or in political and social issues, most generally popular, or of other special prominence is chosen as Supreme Leader.

In the event they find one of them better versed in Islamic regulations, the subjects of the fiqh, or in political and social issues, or possessing general popularity or special prominence for any of the qualifications mentioned in Article 109, they shall elect him as the Leader.

The Leader thus elected by the Assembly of Experts shall assume all the powers of the wilayat al-amr and all the responsibilities arising therefrom.

[14]Article 99 of the constitution declares "The Guardian Council has the responsibility of supervising the elections of the Assembly of Experts for Leadership".

Article 108 states: The law setting out the number and qualifications of the experts [mentioned in the preceding article], the mode of their election, and the code of procedure regulating the sessions during the first term must be drawn up by the fuqaha' on the first Guardian Council, passed by a majority of votes and then finally approved by the Leader of the Revolution.

The power to make any subsequent change or a review of this law, or approval of all the provisions concerning the duties of the experts is vested in themselves.

[5][17] Furthermore, there have been instances of Supreme Leader Ali Khamenei publicly criticizing members of the Assembly, resulting in that member's arrest and an end to their time on the Assembly—an example being Khamenei's denouncing of then-member of the Assembly Ahmad Azari Qomi as a "traitor" after the publishing of an open letter by Qomi criticizing Khamenei, resulting in Qomi's arrest and the eventual rejection by the Guardian Council of his candidacy for re-election to the Assembly.

[20] The assembly has passed laws to require all its members be experts in fiqh (Islamic jurisprudence),[21] authorizing the Guardian Council to vet candidates for ijtihad proficiency using written and oral examinations.

Currently, the average age of the members of the Assembly is over 60, which results in many mid-term elections due to deaths and resignations.

But on Sunday, 26 March 1989 Khomeini dismissed him in a letter: "[...]you are no longer eligible to succeed me as the legitimate leader of the state.

"[27] Following the death of Ruhollah Khomeini on 3 June 1989, the Assembly of Experts chose Ali Khamenei to be his successor as Supreme Leader in what proved to be a smooth transition.

[40] Due to Ali Khamenei's lengthy, unchallenged reign, many believe that the Assembly of Experts has become a ceremonial body without any real power.

[45] There have been instances when the current Supreme Leader's public criticism of members of the Assembly of Experts was followed by their arrest and dismissal.

[46] Mehdi Karroubi, who has been under house arrest since 2011 without trial, by the direct order of Khamenei, said that "the Assembly of Experts, a council of elected clerics charged with electing, supervising and even disqualifying the Supreme Leader, has turned into a ceremonial council that only praises the Leader".