ElBaradei, who won the Nobel Peace Prize for his work as the head of the International Atomic Energy Agency, returned to Cairo in February, adding fuel to speculation he would run for president in 2011.
ElBaradei has called for opposition forces in Egypt to stand united and boycott parliamentary elections set for later this year.
"That will be a message to the regime that it's time to pack your bags and go," he was quoted in Egypt's al-Masry al-Youm newspaper as saying.
Supporters of ElBaradei's National Association for Change have been gathering signatures to back a series of proposed reforms that would ultimately require a redrafting of the Egyptian Constitution.
ElBaradei said he wouldn't seek the presidency unless he could run as an independent candidate, something his reforms address.
Hosni Mubarak, the 82-year-old Egyptian president, has not made his intentions for 2011 known publicly. His National Democratic Party in August, however, backed him unanimously for a sixth term in office.