The ex-premier noted that the CJP and president had in their possession copies of the cipher which was given to the then Pakistani ambassador Asad Majeed Khan by US Assistant Secretary of State Donald Lu.
"The PTI government, as reflected in the last cabinet meeting, was of the view the contents of the cipher clearly reflect a regime change conspiracy to remove PM Imran Khan from the office of the Prime Minister," the letter said.
The vote of no-confidence against the PTI chairman was "engineered", it continued, reasoning the claim with the "shifting allegiance of the then government s allied parties" and the "purchase of loyalty of some members of PTI".
Subsequently, he requested the CJP and the president to "at least examine the cipher which clearly pointed to a foreign regime change conspiracy" and order an inquiry into it.
Imran called on the Supreme Court to constitute a commission to conduct open hearings "in order to establish who all in Pakistan were involved in this regime change conspiracy".