The Election Commission of Pakistan (ECP) on Tuesday issued a notice to the PML-N for the appointment of a new party leader, Dawn News reported.
The ECP in the notice said that under the Political Parties Order 2002, a disqualified lawmaker cannot hold any office in a political party.
The notification also referred to the Supreme Court order on the Panama Papers case, in which Nawaz Sharif was formally asked to step down as prime minister.
The ECP also observed that Article 15 of the PML-N's own party constitution says that if the seat of party president is vacant, it is to be filled within one week's time
The election body asked the PML-N to elect a new party leader and then inform the ECP.
Shortly after the ECP's notification was issued, DawnNews reported that the PML-N was holding a high-level meeting of senior party members, including Finance Minister Ishaq Dar and former interior minister Chaudhry Nisar.
The notice comes a day before Nawaz Sharif is set to travel from Islamabad to his hometown Lahore in what is set to be a 'historic' two-day rally undertaken by the PML-N and ousted prime minister to garner much-needed political mileage in the face of the challenges its government is facing.
Nawaz's rival, Pakistan Tehreek-i-Insaf Chairman Imran Khan, on Monday had urged the PML-N to distance itself from the ousted premier, warning that it would "ruin itself" if it did not do so.
Khan had also alleged that Sharif's plan to travel to Lahore with a cavalcade on GT Road was a "deliberate attempt to undermine the Supreme Court" by calling into question its verdict in the Panama Papers case.
Sharif, while discussing the case with television anchors yesterday, said that the procession was not "a protest" but "a journey back home" that he was undertaking because "risks need to be taken for the country"..