In a new daring letter to the Iran’s Supreme Leader Ayatollah Ali Khamenei, a top Iranian dissident politician Mehdi Karroubi has dismissed him as "unqualified" for running the country.

Referring to the downing of Ukraine Airlines Boeing 737 that killed all 176 passengers and crew January 8, Karroubi has insisted in the letter that Khamenei has none of the qualifications stipulated in the Islamic Republic Constitution for the leadership of the country.

The plane was heading to Kyiv from Tehran when an anti-air missile shot it down outside the Iranian capital city.

After three consecutive days of denials and under internal and international pressure, the Islamic Republic admitted on Saturday that it had "erroneously" shot down the doomed plane.

For long, I had been contemplating to write a comprehensive and detailed letter on Iran's affairs and management, Karroubi says in his letter, adding, the tragedy of downing the Ukraine Airlines Boeing made it even more urgent.

As the Chief Commander of Iran's Armed forces, "you are directly responsible" for shooting down the plane and killing all its crew and passengers, Karroubi reiterates, noting that the present situation in Iran is the outcome of Khamenei's inappropriate meddling in all affairs.

While several media outlets close to Khamenei have claimed that the tragedy was reported to him two days after it occurred, Karroubi has asserted that he was informed about the plane immediately. "It is a shame that you were aware of the incident on Wednesday, and still allowed the military and civil authorities, and the country's propaganda machine to deceive the people for three days. It is also a shame if you were not aware of the disaster for two days.”

Karroubi has concluded, "Undoubtedly, you are not qualified for the leadership as is required by the Constitution."

Furthermore, the twice speaker of the country's parliament (1989-1992 / 2000-2004) has accused Khamenei of having no "insight," "courage," "managerial requirements," and "sufficient power."

Meanwhile, the 82-year-old mid-ranking cleric has asserted that Khamenei's mismanagement is not limited to the downing of a passenger plane.

"You are responsible for the political chain murders (1988-98) since you never allowed a thorough investigation. The responsibility of vote-rigging and brutal suppression of the protesters during the 2009 presidential election… and finally suppressing and killing people protesting a three-fold increase in gasoline prices last November" Karroubi says in the letter.

In a similar letter in 2017, Karroubi had called upon Khamenei to pave the way for amending the Islamic Republic's Constitution.

Karroubi, along with former Prime Minister, Mir Hossein Mousavi, was the primary challenger of the incumbent hardliner president Mahmoud Ahmadinejad in the 2009 presidential election.

Ahmadinejad was officially declared the winner. Mousavi and Karroubi's followers poured into the streets to protest, accusing Khamenei and the Islamic Revolution Guard Corps of "engineering" the election.

Later in February 2011, Karroubi and Mousavi, along with Mousavi’s wife, Zahra Rahnavard, were detained and placed under house arrest after inviting people to demonstrate in favor of what was described as the "Arab Spring." They are still under house arrest.