Pakistan's Prime Minister Imran Khan says he will not resign in the face a no-confidence move against him.
Pakistan's parliament will start proceedings into a no-confidence motion on Friday.
It comes ahead of an International Monetary Fund review on the next tranche of a $6 billion rescue package. The IMF review was scheduled for this week, but has yet to take place.
Opposition parties filed their motion this month, saying the former cricket star had lost his parliamentary majority after some 20 of his party lawmakers defected, calling on him to step down.
It could take seven days before a vote to decide if Mr Khan will be removed takes place.
"I will not resign come what may," Mr Khan said in a statement on Wednesday.
He asked why he should quit under pressure from "crooks".
Along with the defection of nearly 20 of his party lawmakers, some of his coalition partners have suggested they may join the opposition.
Some political analysts and opposition members say Mr Khan has fallen out with Pakistan's powerful military, which has intervened in civilian politics for decades and was seen as instrumental in the success of Mr Khan's upstart party four years ago.
Mr Khan denies the military helped him into office. The military says it does not interfere in politics.
The opposition accuses Mr Khan of mismanaging the economy and foreign policy, which he denies.
No Pakistani prime minister has ever completed a full five-year term in office.
Pakistan's next general election is due by late 2023, but Interior Minister Sheikh Rasheed Ahmad suggested at a news conference an election might be held early to defuse the looming confrontation.