Lt Gen (r) Tariq Khan on Friday excused himself from heading the commission formed by the government to investigate the "letter" purportedly containing details of a "foreign conspiracy" to oust Prime Minister Imran Khan.

In his statement, Gen Khan said said the commission could not last beyond the incumbent government's tenure, which was expected to end in two days.

He said voting on the no-confidence resolution against PM Imran — due to take place tomorrow — would bring into power a new government, which would "dissolve the commission or not cooperate with it, making it dysfunctional".

His statement came a couple of hours after Information Minister Fawad Chaudhry said the commission, led by the retired general, would investigate all the "characters" behind the no-trust move against PM Imran and expose them in front of the nation.

"It [the commission] will see if the communique exists and whether it contains the threat of regime change. The commission will also disclose the local handlers who were used to take forward this foreign conspiracy," the minister had said.

"Of course, not everyone from the opposition was involved in it. But there were some people who knew what the conspiracy was, who was behind it and where it came from."

He added that the commission would review the aforementioned points within 90 days and form its own investigative teams.

The letter

PM Imran had at a public rally on March 27 claimed that the move to topple his government was the result of a foreign conspiracy.

"Foreign funding is being used to change the government. Money is coming from abroad and people inside the country are being used. Some of them are unaware they are being used and some are intentionally using this money against us," he had alleged.

Though he did not initially provide specific details about the threatening letter, he subsequently opened up a bit because of critics doubting his claim. The government initially offered to share the letter with the chief justice of Pakistan, but later the prime minister also briefed his cabinet members about the contents of the letter.

In view of the legal bar on disclosing classified documents, a group of journalists were then provided with minutes of the cabinet meeting at their interaction with the prime minister.

The prime minister later named the country as the United States and it turned out that his allegation was based on a cable received from Ambassador Asad Majeed in which he had reported about a meeting with Assistant Secretary of State for South and Central Asia Affairs Donald Lu.

Asad Majeed had reportedly said that Donald Lu warned that Imran Khan's continuation in office, who was facing a vote of no confidence, would have repercussions for bilateral relations. The US was said to be annoyed with PM Imran over his "independent foreign policy" and visit to Moscow.

It was interpreted by the government as a threat.

Contradictory claims have emerged from Islamabad and Washington about the meeting between Ambassador Majeed and Lu after PM Imran's claim.

A senior Pakistani official had told Dawn the language used in the meeting by the American side was unusually harsh.

The National Security Committee, which is Pakistan's top security body, headed by the prime minister and which includes the three services chief as well as the intelligence chief, held a meeting on March 31, and expressed grave concern at the communication, terming the language used by the foreign official as undiplomatic.

In a statement, the body said this communication amounted to "blatant interference in the internal affairs of Pakistan by the country in question", terming it "unacceptable under any circumstances".

"The committee decided that Pakistan will issue a strong demarche to the country in question both in Islamabad and in the country's capital through proper channel in keeping with diplomatic norms," according to the statement.