ISLAMABAD — Concerns have mounted over the political future of Pakistan Prime Minister Nawaz Sharif after his planned return to Islamabad this week was cancelled on health grounds, following his open heart surgery in London.

“Due to an infection in one of the incisions in his (Mr Sharif’s) leg, he is suffering from fever. Doctors are treating him for the infection,” said an official statement. With his scheduled return to Islamabad on Tuesday from his native city of Lahore further delayed, Mr Sharif has been away from the Pakistani capital for seven weeks.

He returned to Lahore on July 9 surrounded by questions over his ability to continue running the government from a distance. “You can’t be an autopilot Prime Minister indefinitely. This (delay) will add to complications for the Prime Minister,” said a senior Western diplomat.

Ahead of the surgery, Mr Sharif was dogged by questions from the opposition when three of his children were found to own significant overseas assets that were revealed in the leaked Panama papers. These included properties overlooking London’s Hyde Park. Mr Sharif insisted that his family’s overseas assets were gained from profits from the sale of steel businesses in Saudi Arabia.

But analysts warn that Mr Sharif’s future has been overshadowed by his refusal to consider appointing a successor, even temporarily, as he deals with his health and the fallout from the Panama papers.

“This episode shows that the entire concept of a smooth transition either within political parties or the parliament simply does not exist in Pakistan,” said retired Lieutenant General Talat Masood, a commentator on security and political affairs.

“The Prime Minister’s absence from Pakistan over these seven weeks shows that the entire democratic and parliamentary system remains fragile. The country is rudderless and there is no effort even to create a system if the Prime Minister needs to go on an extended leave.”

However, politicians from Mr Sharif’s Pakistan Muslim League — Nawaz (PML-N) — said the Prime Minister also faced pressure from the military, led by General Raheel Sharif, the army’s chief of staff, “after recent noises seeking an army intervention”.

In 1999, Mr Sharif’s decision to remove General Pervez Musharraf, the army’s chief at the time, and appoint a chosen general led to a coup and a subsequent nine-year military rule. Gen Sharif has stated this year that he has no intention of extending his tenure which ends in November, while senior army generals insist that they have no plans to intervene.

But recent posters displayed across large cities from a little-known political group — “Move on Pakistan” — urging Gen Sharif to lead the country, have prompted speculation over the army preparing to step in.

“As you can see, the Prime Minister is a nervous man as he seeks to protect the democratic framework,” said one senior PML-N politician.

Opposition leaders, notably Mr Imran Khan, the former cricket star turned politician, claim Mr Sharif is running a “monarchical government” which remains disconnected from key challenges and has become ineffective.

In a widely noticed move to placate popular resentment, Mr Sharif’s government recently gave new incentives to farmers who constitute up to 60 per cent of the population, and have suffered from falling global commodity prices in the past 18 months.

Backbenchers in Parliament from the PML-N who represent rural constituencies criticise Mr Sharif for a focus mainly on the urban economy since being elected in 2013, while ignoring the rural belt.

“With the next elections due in 2018, our leaders are just waking up now to the realities of Pakistan,” said one. “In the past three years, the focus has been more on fancy trains and fancy bus projects.”

As Pakistanis awaited news of Mr Sharif’s return to Islamabad, some questioned whether it is already too late for him to turn the emerging tide against his government.

“We don’t know the exact status of Nawaz Sharif’s health. Once that becomes clear, only then will we know if he can solve all the other problems,” concluded the Western diplomat.