A main ally of Pakistani Prime Minister Imran Khan quit his ruling coalition on Wednesday after reaching a pact with opposition parties seeking to oust him, signalling Khan may be running out of options as he tries to stay on in power.
Former cricket star Khan, 69, is battling a series of defections from his ruling alliance and an increasingly united opposition trying to force him from office in a no-confidence vote due on Monday.
Khan's ouster would likely mean another round of instability in the nuclear-armed country, in which the military has a long record of intervening in politics.
"We have sent our resignations to the prime minister," Amin-ul-Haq, a member of Khan's cabinet from the Muttahida Qaumi Movement (MQM), told reporters.
Khan's party does not have a simple majority in the National Assembly by itself and needs the support of coalition allies and the MQM, based in the southern port city of Karachi, has been his biggest ally in parliament.
Opposition parties accuse Khan of mismanaging the economy, foreign policy and resorting to heavy-handed measures against critics.
Earlier, the MQM said it was joining an opposition bid to oust Khan in a no-confidence.
Senior MQM member Nasreen Jalil told reporters her party and those opposed to Khan had reviewed their agreement and they would announce details later in the day.
"The MQM coordination committee has endorsed the agreement with the joint opposition," she said.