Both sides deny it, but it's widely acknowledged that Imran Khan came to power with the help of Pakistan's powerful army and intelligence services - and now he has fallen out with them, reports said.
The Pakistan Army began to grow increasingly frustrated with Khan's failure to deliver good governance, particularly in Punjab, and perhaps at how they were being publicly blamed for bringing him into power by the opposition, the BBC reported.
Most crucially, a rift began to appear between Army chief, Gen Qamar Javed Bajwa and former ISI chief and current Peshawar Corps Commander, Lt Gen Faiz Hameed, who was widely seen as hoping to become the next Army chief.
Lt Gen Hameed was apparently so confident of his prospects that he had even previously told officials in neighbouring Afghanistan he would be the next man in charge of the army, BBC reported.
However, one source close to the military said that while Lt Gen Hameed was seen as someone who could handle "dirty jobs" effectively, a reference to manipulating politicians or silencing critics, he was not seen as someone fit "to lead the institution".
The tension between the two powerful figures was noticed during a private interaction with influential commentators last summer. One journalist asked a question, only to be told by Hameed, then head of the ISI, that time had run out.
"I'm the chief," interjected Gen Bajwa curtly, "and I'll decide when we're done," before proceeding to take the question and answer it at leisure, BBC reported.
In October, the dispute escalated and enveloped Imran Khan. Gen Bajwa was understood to want a new man in charge of the intelligence services, and the army announced a change in roles.
Khan, however, who had developed a close relationship with Lt Gen Hameed, resisted, apparently wanting him to stay on until elections had taken place - the assumption being that Lt Gen Hameed could once again help ensure Khan's victory.
The Prime Minister held off issuing a formal notification approving the change of posting for nearly three weeks before eventually relenting. The now visible cracks between the military and Imran Khan's government emboldened the opposition.
Imran Khan had also earlier "scuttled" an attempt championed by Gen Bajwa to partially restore trade with regional rival India, "because of the political cost". Ironically, previous civilian governments have fallen foul of the Pakistani military because they have been in favour of improving ties with India - but at that stage, the military wasn't.
Journalist Kamran Yousaf told the BBC that the military had been involved in "managing" Imran Khan's allies and slim majority in government. "Once that support was missing, his downfall was inevitable," he said, BBC reported.