Mansour would take the oath in front of the members of the Constitutional Court assembly, a judicial source in the court told Anadolu Agency.
The source, who declined to be identified, added that contacts were being made with the assembly members to come on Thursday to attend the swearing-in ceremony.
Defense Minister Abdel Fatah El Sisi has announced that Mansour will be the interim president of Egypt until early presidential election is held.
He added that a roadmap for the future of Egypt also included temporarily suspending the constitution, forming a coalition government of technocrats and holding early presidential election.
Mansour before assuming his new post as head of the Egyptian Constitutional Court, has got a new job as interim president of Egypt.
Mansour will likely take the oath on Thursday in front of the members of the Constitutional Court assembly, becoming the first head of the Constitutional Court to become an interim president.
Mansour, born in 1945, was appointed deputy head of the constitutional court in 1992 and remained in his post until he was chosen by the court assembly as new Constitutional Court head last May.
He was supposed to assume his new post as of July 1, but now instead he would serve as interim president of Egypt until early presidential election is held.