Thee Association of Arab Tribes in Egypt, which represents some 15 million people, confirmed the right to self-determination and to choose one's president in accordance with the constitution.
In a statement on Monday, the association said: "We highly appreciate what the sons of Egypt did on 25 January, sacrificing their blood for their right to justice, freedom, equality and to change the regime.”
The statement added: "We also appreciate the response of the regime to many demands of the masses, and call on it to quickly meet the remaining demands in accordance with the constitution."
Demonstrations, which have been staged across Egypt since 25 January, are calling for the resignation of President Hosni Mubarak.
The statement also said that "the sacrifice of blood forces the government to realize that it represents the people, the source of power. They have the right to demand that the constitution limit the powers of the president."
"As partners in this country, and since we represent a large number of people, we reiterate our right to participate in determining the person who will rule us, even for a transitional period, as long as democracy is our aim,” the statement said.
"We call on everyone to work together for a peaceful transition of power in accordance with the constitution, and we reject all types of foreign interference," the statement concluded.