Former prime minister and PML-N leader Shahid Khaqan Abbasi demanded on Tuesday that a session of parliament be called "immediately" tomorrow (Wednesday) and the letter — which Prime Minister Imran Khan claimed during the PTI's March 27 rally contained evidence of a "foreign-funded conspiracy" to topple his government — be shared with parliamentarians.

The prime minister had said while addressing the rally that he was in possession of evidence — a letter — that would prove his claims of attempts being made from abroad to influence Pakistan's foreign policy and efforts being made "through foreign money to change the government in Pakistan".

"Mostly inadvertently, but some people are using money against us. We know from what places attempts are being made to pressure us. We have been threatened in writing but we will not compromise on national interest," he had said.

Addressing a press conference in Islamabad today, Abbasi equated PM Imran's claim to a threat to Pakistan and further demanded that all diplomatic relations be broken with the country that had "threatened Pakistan" through the letter and its envoy be expelled.

"This is how a sovereign country reacts when it is threatened," he added.

Abbasi also referred to federal ministers Asad Umar and Fawad Chaudhry announcing earlier in the day that PM Imran was willing to show the letter to Chief Justice of Pakistan (CJP) Umar Ata Bandial and that its contents were linked to the country's foreign policy.

"The opposition has grave concerns over some of the details shared by the premier and his ministers and there is a need to get to the bottom of these matters," he said. "If the prime minister is speaking the truth, then this is how you should act ... and if not, come to parliament and apologise."

Specifically speaking about PM Imran's March 27 speech, Abbasi said: "He (PM Imran) was crying about receiving threats. The person who told others not to worry seemed worried himself. Whether he was worried about the no-confidence motion [filed against him in the National Assembly], his [looming] ouster or something else, we do not know. But this is a reality that the prime minister of a nation of 230 million Muslims waved a paper and said he had been receiving threats."

He showed the paper as proof of the threat, Abbasi said, adding that "keeping politics aside, I, too, am worried about my prime minister crying about receiving threats" as, in this case, the threat had been made to Pakistan.

"Threats are not made to a prime minister but a country," he remarked.

Therefore, he said, he was demanding that a session of parliament be convened on an immediate basis tomorrow and the letter be shared with parliamentarians.

"And if this is a secretive matter, an in-camera session should be held," Abbasi continued, adding that parliamentarians should be told which country had dared to threaten Pakistan.

"No one had dared to do so in our 74-year-long history," he said, asking, "Are we so weak now that we are being threatened through a letter?"

"Entire parliament should be taken into confidence on this," he added.

The prime minister, he said, should come to the parliament tomorrow and tell parliamentarians who had threatened Pakistan. "We are with him on this. We are with him [on this] for the remaining six days for which he will remain the prime minister".

"Don't we have the courage to name [that country]?" he added.

"A threat has been made to our country and we have to respond to it collectively. This is not just about Imran Khan and his two ministers. This is about 230m people of Pakistan and there is a need to respond to this threat," Abbasi stressed.

Abbasi said if the government would not show the letter now, "it will be shown after April 4. It will be published in newspapers".

"If it is not presented in parliament now, it would be presented next week, that is if it exists at all. The real issue is that nobody knows whether the letter exists."

"And why was it not shared earlier? Why did you keep it hidden?" Abbasi questioned.

The PML-N leader said it should also be discussed in the parliament why the letter had surfaced right before the start of no-confidence proceedings against PM Imran.

Further referring to federal ministers Asad Umar and Fawad Chaudhry alleging that and PML-N supremo Nawaz Sharif was involved in the conspiracy that the letter detailed, Abbasi said the two ministers should either show proof of their claims in the court or apologise.

"Because you have not accused an ordinary prime minister but the one who made this country an atomic power," Abbasi remarked.

He added that the government should not put the country's foreign policy at stake to stay in power and if a threat had been made, the matter should be raised in the National Security Committee and parliament.

"We will fight these external dangers together, but if you are lying, you will have to answer to the nation. The decision is yours. Either [share the letter] in parliament or apologise," Abbasi said.