More than 100 politicians loyal to Pakistan's ousted prime minister Imran Khan resigned on Monday, creating a headache for the new, Western-friendly incumbent Shehbaz Sharif as he tries to drag his country out of political and economic crisis.
Parliament's election of Mr Sharif, 70, as prime minister on Monday followed a week-long constitutional crisis that reached a climax on Sunday when Mr Khan, 69, lost a no-confidence vote in parliament.
His departure from power sparked street protests and a mass resignation of MPs from Khan's Pakistan Tehreek-e-Insaf party in protest at the impending change of government.
If the resignations are accepted by the speaker, Pakistan faces a prospect of more than 100 by-elections within two months, a major distraction for Mr Sharif and his coalition partners and a potential platform for Khan to mobilise his support.
That in turn could ensure the nuclear-armed nation of 220 million people remains prone to political and economic turbulence.
Mr Sharif has a reputation domestically as an effective administrator more than as a politician. He is the younger brother of three-time prime minister Nawaz Sharif.
Analysts say Mr Shehbaz, unlike Mr Nawaz, enjoys amicable relations with Pakistan's military, which traditionally controls foreign and defence policy.
After Monday's vote, Mr Sharif vowed to tackle an economic malaise that has seen the rupee hit an all-time low and the central bank implement the biggest hike in interest rates in decades last week.
"If we have to save the sinking boat, what we all need is hard work, and unity, unity and unity," he told parliament.
"We are beginning a new era of development today."
He took the oath of office at Pakistan's presidential residence late on Monday at a ceremony packed with politicians and leaders from the combined opposition.
Reset ties
The younger Mr Sharif emerged as the leader of a united opposition to topple Mr Khan, a former cricket star who has claimed that the United States was behind his downfall, an assertion that Washington denies.
Mr Sharif said in an interview last week good relations with the United States were critical for Pakistan for better or for worse, in stark contrast to Khan's prickly ties to Washington.
In his maiden speech, he also spoke of improving relations with neighbours India and China.
"We want good relations with India but a durable peace can't be possible without Kashmir's solution," he said, referring to the contested Himalayan territory the countries have fought several wars over.
He said his government will speed up construction of the $60 billion China-Pakistan Economic Corridor (CPEC) - a part of Beijing's Belt and Road Initiative.
Military fallout
No elected prime minister has completed a full term in Pakistan since it won independence from colonial power Great Britain in 1947, though Mr Khan is the first to be removed by a no-confidence vote.
The military has ruled the country for almost half its nearly 75-year history. It viewed Mr Khan and his conservative agenda favourably when he won election in 2018.
That support waned after a falling-out over the appointment of a military intelligence chief and economic troubles.
Mr Khan remained defiant following his defeat in parliament.
Thousands of his supporters in several cities held protests against his ousting that went on until Monday's early hours.
Nawaz Sharif was barred by the Supreme Court in 2017 from holding public office and subsequently went abroad for medical treatment after serving just a few months of a 10-year jail sentence for corruption charges.
"There can't be any bigger insult to this country," Mr Khan, ousted in the early hours of Sunday, told reporters on Monday on the prospect of Shehbaz Sharif being elected.
