The civilian government led by the Pakistan People's Party (PPP) made history by completing its full five-year term, but Taliban attacks and record levels of violence against Shiite Muslims have raised fears about security for the polls.
"We are trying to create consensus over caretaker setup," former information minister PPP spokesman Qamar Zaman Kaira said.
"The government has some reservations on the names proposed by the leader of the opposition, but we are still open to listen to opposition," Kaira said.
According to Pakistan's constitution, Prime Minister Raja Pervez Ashraf and opposition leader Chaudhry Nisar Ali Khan now have three days (until Tuesday) to agree on the caretaker prime minister.
If they do not reach an agreement, then the matter will go to an eight-member parliamentary committee consisting of members of the recently dissolved National Assembly.
The committee, which consists of four members from the government and four from opposition parties would have to decide on the caretaker PM within three days failing which the matter would go to the Election Commission of Pakistan.
The election commission's decision, to be taken within two days, would be considered final.
Ashraf will continue in his seat as premier without his cabinet till a caretaker prime minister is selected.
The main opposition Pakistan Muslim League (PML-N) led by former prime minister Nawaz Sharif said that consultations on the caretaker prime minister were taking place within the party and with other opposition parties.
"Consultations are still taking place," Siddiqul Farooq, a spokesman for PML-N, told AFP.
"I hope that the name of caretaker prime minister will be decided by Prime Minister and the Leader of Opposition," he said.