Justice Gulzar Ahmed (first from right) was nominated as caretaker PM by Imran Khan.
Embattled Pakistani leader Imran Khan on Monday nominated former Chief Justice Gulzar Ahmed for the office of caretaker Prime Minister.
Former Information Minister and senior leader of the Pakistan Tehreek-e-Insaf party Fawad Chaudhry said that Mr Khan made the decision after approval from the party's core committee.
The announcement comes after President Arif Alvi sent letters to Mr Khan and Leader of the Opposition Shehbaz Sharif on Monday seeking suggestions for the appointment of a caretaker Prime Minister.
"In response to the President's letter, after consultation and approval by the PTI Core Committee, Prime Minister Imran Khan has nominated Pakistan's former chief justice Gulzar Ahmed for the post of caretaker Prime Minister," Mr Chaudhry said.
In his letter, President Alvi told them in case they do not agree on the appointment within three days of the dissolution of the Parliament, they shall forward two nominees each to a committee to be constituted by the Speaker, comprising eight members of the outgoing assembly, or the Senate, or both, having equal representation from the treasury and the opposition.
The Constitution has empowered the president to appoint a caretaker prime minister in consultation with the prime minister and the leader of the Opposition in the outgoing National Assembly, the President's Secretariat said in a statement.
Mr Khan is supposed to continue as Prime Minister until a caretaker premier is appointed, according to the notification issued by President Alvi.
Meanwhile, Shehbaz Sharif said that he would not take part in the process and termed it "illegal", saying that the President and Mr Khan had broken the law and questioned how they could approach the Opposition.
Reacting to Mr Sharif's decision, outgoing information minister Fawad Chaudhry said: "Pakistan is gearing up for the elections... Shehbaz has said he will not be a part of the process, that's his choice.
"We have sent two names (to the president) today. If (Shehbaz) does not send the names within seven days, one of these will be finalised".
Earlier in the day, the Cabinet Secretariat issued a notification stating that Khan had "ceased to hold the office of the prime minister of Pakistan with immediate effect".
However, under Article 94 of the Constitution, the president "may ask the Prime Minister to continue to hold office until his successor enters upon the office of Prime Minister".
"Mr. Imran Ahmad Khan Niazi, shall continue as Prime Minister till the appointment of caretaker Prime Minister under Article 224 A (4) of the Constitution of the Islamic Republic of Pakistan," the President said on Twitter.
President Alvi had dissolved the NA on the advice of Prime Minister Khan, minutes after Deputy Speaker Qasim Suri rejected a no-confidence motion against the premier, who had effectively lost the majority in the 342-member lower house of Parliament.
Supreme Court Chief Justice Umar Ata Bandial, after taking a suo motu cognizance of the political situation in the country, said that all orders and actions initiated by the Prime Minister and the President regarding the dissolution of the National Assembly will be subject to the court's order as he adjourned for one day the hearing of the high-profile case.
A three-member bench held the initial hearing despite the weekend and issued notices to all the respondents, including President Alvi and Deputy Speaker of the NA Suri.
The Supreme Court ordered all parties not to take any "unconstitutional" measures and adjourned the hearing until Monday.
Ahsan Bhoon, President, Supreme Court Bar, said that the action of the prime minister and deputy speaker was against the constitution and "they should be prosecuted for treason under Article 6 of the constitution.
The crisis erupted after Suri rejected the no-confidence motion, providing Prime Minister Khan to send an advice to the president of the country to dissolve Parliament, which he could not do until any outcome of the no-confidence vote.
Leading constitutional lawyer Salman Akram Raja said that the "entire procure by the deputy speaker and the advice by the premier to dissolve the assembly was unconstitutional".
Mr Raja said the illegality of the ruling would also make the advice as illegal as the prime minister cannot give advice to the assembly after a no-confidence motion was presented in the parliament against him.