Former director-general of the Inter-Services Intelligence (ISI), retired Lt Gen Zaheerul Islam, has said he never asked for the resignation of former premier and PML-N supremo Nawaz Sharif in 2014.

"I never sent anyone to convey any such message to [Nawaz], this is absolutely wrong," he said while speaking to The News.

Instead, Islam insisted that at every stage of the 2014 sit-in, he had advised the PML-N government to engage politically with the PTI and the Pakistan Awami Tehreek (PAT) to end the protest. Islam, however, was reluctant to talk further on the subject, according to the report.

Islam's comments come days after Nawaz claimed that during his last stint as premier, at a time when Imran Khan was leading the 2014 Islamabad sit-in, the former ISI director-general conveyed a message in the middle of the night, asking for Nawaz's resignation or else the consequences could include a martial law imposed in the country.

"I was told to step down and go home. I said whatever you want to do, do it […] I will not resign [from the office of the prime minister],” Nawaz said, referring to Islam's alleged message, during his Sept 30 video address to his party.

Mocking Nawaz's claim, PM Imran, in an interview with Samaa TV, said: "You were the prime minister, [how] does he have the courage to say that to you?

"If someone tells that to me, I will demand his resignation. I am the democratically elected prime minister; who can dare tell me to step down?"

Later, addressing a lawyer's forum ceremony, PM Imran once again took Nawaz to task for his claim.

"Why did he [Islam] say that? And why did you [Nawaz] silently hear that? Because Zaheerul Islam knew how much money you had stolen."

Imran went on to say that opposition parties' real issue with the military was that unlike other institutions, opposition was unable to "control" the ISI after the agency "found out" about their alleged corruption.

Nawaz "fought with every army chief" because he wanted to turn the military into Punjab police, Imran said.

Nawaz, who made his political comeback last month, after a year-long hiatus, has in recent weeks levelled serious allegations of political interference against the armed forces.