Imran Khan survived a move to oust him as Pakistan's prime minister on Sunday, getting a reprieve when the deputy speaker of parliament blocked a no-confidence motion as unconstitutional.
Khan's fate was not immediately clear, leading to fresh political instability in the nuclear-armed country of 220 million people.
The opposition immediately vowed to challenge the block on the vote, made by a member of the premier's political party, while Khan advised the country's president to dissolve parliament and called on the nation to prepare for fresh elections.
"I've sent advice to the president to dissolve assemblies," Khan said in a televised address, referring to national and state legislatures.
Bilawal Bhutto Zardari, head of the opposition Pakistan People's Party (PPP), promised a sit-in at the parliament and told reporters, "We are also moving to the Supreme Court today."
The opposition blames Khan for failing to revive the economy and crackdown on corruption. He has said, without citing evidence, that the move to oust him was orchestrated by the United States, a claim Washington denies.
POLITICAL SURVIVAL ON THE LINE
The opposition and analysts say that Khan, who rose to power in 2018 riding on the powerful military's support, had fallen out with it, a charge he and the military denied.
No prime minister has finished a full five-year term since independence from Britain in 1947, and generals on several occasions have ruled the country, which is perennially at odds with fellow nuclear-armed neighbor India.
If the vote had gone through and the opposition remained united, the former cricket star who surged to power in 2018 but recently lost his parliamentary majority, would have been out of office.
With coalition partners and some of his own lawmakers defecting earlier in the week, Khan had looked set to fall below the 172 votes needed to survive the no-confidence vote. Read full story
A prominent newspaper had recently said Khan was "as good as gone", but he had urged his supporters to take to the streets on Sunday ahead of the planned vote.
On the streets of the capital Islamabad, there was a heavy police and paramilitary presence, with shipping containers used to block off roads, according to a Reuters witness.
Police were seen detaining three supporters of Khan's ruling Pakistan Tehreek-e-Insaf party outside parliament, but the streets were otherwise calm.