If Shehbaz Sharif does take on the role, he faces immediate challenges such as the country's crumbling economy, which has been hit by high inflation, a tumbling local currency and rapidly declining foreign exchange reserves.
Imran Khan has been dismissed as Pakistan's prime minister after losing a no-confidence vote, paving the way for an unlikely opposition alliance that faces the same issues that bedevilled Khan.
A new premier will be chosen on Monday, with centrist Pakistan Muslim League-N (PML-N) chief Shehbaz Sharif already anointed to lead the nuclear-armed nation of 220 million people.
His first task will be to form a cabinet that will also draw heavily from the centre-left Pakistan Peoples Party (PPP), as well as find space for the smaller conservative Jamiatul Ulema-e-Islam-F (JUI-F) group.
The PPP and PML-N are dynastic parties that have dominated Pakistani politics for decades – usually as bitter rivals – and their relations are sure to fray in the lead-up to the next election, which must be held by October 2023.
Shehbaz Sharif is the brother of former three-time prime minister Nawaz Sharif, while PPP leader Bilawal Bhutto Zardari is the son of former president Asif Ali Zardari and assassinated ex-premier Benazir Bhutto.
Call for protests
Khan has called on supporters to take to the streets in protest.
He has claimed the US worked behind the scenes to bring him down, purportedly because of Washington's displeasure over his independent foreign policy choices, which often favour China and Russia.
Khan said America was deeply disturbed by his visit to Russia and his meeting with Russian President Vladimir Putin on February 24, the start of the devastating conflict in Ukraine.
The US State Department has denied his allegations.
Elizabeth Threlkeld, a Pakistan expert at the US-based The Stimson Center, said that even as prime minister, Khan often played the role of opposition leader.
"His removal would see him to a role he knows well, armed with a narrative of victimhood from unfounded claims of international interference,” she said. “His base will remain loyal, though I expect both his controversial attempt to remain in power and reduced military backing will lose him less committed supporters.”
Khan would seem to have few options going forward.
General elections are not scheduled before August 2023.
Even if the new prime minister favours early elections, this would likely not happen before October. The Pakistan Election Commission, which oversees polls, told the Supreme Court last week it had still to finish re-aligning constituencies in line with the results of a 2017 census before polls could be held.
Khan's opponents say the army helped him win the 2018 elections after it had fallen out with Nawaz Sharif, who was convicted of corruption after being named in the so-called Panama Papers. These papers are a collection of leaked secret financial documents showing how some of the world’s richest hide their money and involving a global law firm based in Panama.
Pakistan’s Supreme Court disqualified Sharif from holding office. He lives in London in self-imposed exile after being convicted in a Pakistani court of corruption. He was sentenced to 10 years in jail.
Fissures in Khan's relationship with the army began last November after he squabbled with the powerful Army Chief Gen. Qamar Javed Bajwa over the appointment of the new intelligence chief.
Last weekend, Bajwa appeared to distance himself from Khan’s anti-U.S. attacks saying Pakistan wants good relations with Washington, its largest export trading partner and with China.