[2][3] He hails from an influential transnational clerical family, and is the younger brother of Muhammad al-Shirazi, and considered his successor.

However, after the emergence[citation needed] of controversial Kuwaiti cleric, Yasser al-Habib, and his claimed affiliation with al-Shirazi–al-Shirazi's marja'iyya was placed under scrutiny.

[10] al-Shirazi's followers form the Shia majority in Saudi Arabia, under the leadership of Sheikh Hassan al-Saffar, an activist and proponent of sectarian reconciliation.

His view is a minority ruling, only shared by Sheikh Nasser Makarim Shirazi (in a slightly different version[12]) and a few other jurists.

He explicitly says that this is due to the understanding of the words above, not due to la haraj (principle that states no Islamic law can be the cause of extreme hardship) i.e. even if it does not cause difficulty, you are still required to fast a maximum of 17.5 hours[13] The consequence of the viewpoint of al-Shirazi (as well as Makarim Shirazi) is that if the fast is longer than 17.5 hours, you should revert to times with mu'tadil lengths of day e.g.

[16] He was prosecuted after a lecture comparing Iran's government—the Guardianship of the Islamic Jurist (velayat-e faqih)—to a regime of "pharaohs".

[10] His arrest fuelled debates on whether Iran's supreme leader Ali Khamenei should be able to claim divine sanction for unlimited state powers.

[8] Protests against his arrest were held at the Iranian consulate in Karbala, Basra and Najaf, Kuwait City and Iran's embassies in Baghdad and London.