In elections where he was the only candidate, Younis Makhyoun was elected as chairman of the Salafi (ultraconservative) Nour Party on Wednesday, to replace Emad AbdelGhafour who resigned last week.
"The Quran (Islamic holy book) is the constitution," members chanted following the victory of Makhyoun.
The Nour Party occupied second place in last year's parliamentary elections following the Muslim Brotherhood's Freedom and Justice Party.
The ultraconservative party witnessed division last month when a large number of its members withdrew their memberships.
Now that a new constitution has been put into law, vote is expected to take place to elect a new People's Assembly in April, officials told Reuters on Wednesday.
Meanwhile, members who withdrew from the party decided to form a new party, headed by disqualified presidential candidate Hazem Salah Abu Ismail, to compete in the upcoming elections.