A senior judge of Lahore High Court, Justice Sheikh Azmat Saeed, will head the full bench while Justices Nasir Saeed Sheikh and Chaudhry Shahid Saeed will be its members.
The bench will start its proceedings next week.
Lawyer A K Dogar filed the petitions on behalf of two petitioners and asked the court to direct President Zardari to disassociate himself from the political office of chief of the Pakistan People's Party in light of a decision given by a full bench of the same court in May.
Rana Ilamuddin Ghazi, another lawyer, said in his petition that the full bench of the High Court, in its earlier order, had declared the President's involvement in political activities as unconstitutional.
He said Zardari had not disassociated himself from political activities at the earliest as was expected by the court, nor had he stopped "misusing" the presidency for the purposes of his political party.
The petition against the Prime Minister was filed by Allah Bakhsh Gondal, who contended that Gilani, by deliberately defying the Supreme Court’s orders and repeatedly attempting to subvert the Constitution, had ceased to hold the office by automatic operation of Articles 5, 6 and 92(2) of the Constitution.
Gondal asked the court to declare the Prime Minister disqualified to hold his office and sought action against him under charges of high treason.