The first draft of Egypt's new constitution is to be finalised this week, Mahmoud Ghozlan, a Muslim Brotherhood spokesperson, told the Al-Ahram Arabic news website on Monday.
The draft will be discussed and revised over the next two weeks and then voted on, he said.
However, Ghozlan confirmed that the constituent assembly is still divided on certain articles.
The Supreme Administrative Court is to rule on the constitutionality of the assembly on 2 October. If the assembly is dissolved by the court, Ghozlan said, President Mohamed Morsi would form a new assembly with the same composition as the current one.
Critics have claimed the current assembly is unrepresentative and Islamist dominated. The assembly has experienced mass walkouts from liberal and leftist forces to allow for greater representation of women and Copts, and to condemn the "Islamist monopoly."
Parliament's lower house, which chose the assembly's 100 members, was found to be unconstitutional and dissolved following a court order in June.