ISLAMABAD — Pakistan's ruling party will appoint Shahid Khaqan Abbasi as interim prime minister after the ouster of Nawaz Sharif, two sources close to the toppled premier said on Saturday, while Sharif's brother has been chosen as his long-term successor.

Abbasi, 58, is a staunch Sharif loyalist and had been the petroleum minister in his Cabinet until Friday, when Sharif resigned following a Supreme Court disqualification after a corruption probe.

One senior PML-N official close to Sharif said Abbasi should be appointed "in an hour", while a second source confirmed the appointment and the plan to have Abbasi in place until Shahbaz contests a parliamentary seat and becomes eligible to take over.

Shahbaz Sharif, 65, the chief minister of the vast Punjab province that accounts for more than half of Pakistan's 190 million people, will also need to resign from his regional post.

Nawaz Sharif's resignation on Friday has plunged the nuclear-armed nation into political turmoil after several years of relative stability. Sharif quit after he was disqualified by the Supreme Court over undeclared assets.

The court has also ordered a criminal investigation into Sharif, 67, and his family. The ruling PML-N party has a strong majority in parliament so should have no problem appointing its choice as the new prime minister.

Sharif has always denied any wrongdoing and his toppling has rekindled concerns about Pakistan's democracy after a member of his Pakistan Muslim League-Nawaz (PML-N) party hinted that elements of the powerful military were in some way involved.

"We know very well what the crime of Nawaz Sharif and the Muslim League is. What do we ask for? We ask for civilian supremacy in Pakistan," Railways Minister Khawaja Saad Rafiq told a news briefing.

Questioned further, however, Rafiq would not name the military as a whole. The army has not commented on Sharif's removal, or allegations they were involved. In the past the army has dismissed claims they are behind Supreme Court's push against Sharif.

Rafiq told Geo TV late on Friday that it was not yet decided if the interim leader would be in power for a 45-day period or until the next general election, which have to held by early August 2018.

Whoever replaces Sharif will have to tackle Pakistan's worsening ties with the United States, frayed relations with India, and persistent attacks by militants including the Pakistani Taliban and the Daesh (so-called IS) group.

The state of the economy — which is growing at its fastest pace in a decade — has also began to concern economists, who are warning an over-valued currency is hurting exports and urge action over a ballooning current account deficit.

Shahbaz Sharif has been in charge of Punjab since 2008, building a reputation as a competent administrator focused on building infrastructure. He also has better relations with the military than his brother.

The opposition has hailed the Supreme Court's decision to remove Nawaz Sharif as a sign of progress and greater accountability in a nation where impunity is rife. "They have given Pakistan hope. This is what everyone is celebrating," Imran Khan, cricketer-turned-politician who leads the opposition PTI party, said on Friday. Khan's PTI party plans to hold a victory rally on Sunday.

Sharif was investigated for corruption after the "Panama Papers" data leak revealed his family used offshore companies to buy posh London apartments. But his ouster was down to the little-used Article 62 of the Constitution, which allows for dismissal from office of anyone deemed dishonest.

Sharif's allies have privately spoken of a "judicial coup" and say every parliamentarian would likely fail the Article 62 test, including opposition leader Khan, who also has a pending Supreme Court case against him over undeclared income. — Reuters