ElBaradei, the former U.N. nuclear watchdog chief, returned to Cairo in February to a warm welcome, sparking early rumors he would challenge 82-year-old President Hosni Mubarak in presidential elections in 2011.
He formed a National Association for Change but backed off amid criticism he wasn't taking reforms seriously. The Muslim Brotherhood, Egypt's largest opposition group, ignored his calls for a boycott of last month's parliamentary election.
ElBaradei in a 12-minute video posted on his Facebook page said he was focusing his campaign of civil disobedience on the 2011 election.
The ruling National Democratic Party was faced with its "last chance to review itself, and begin again the process of democratic reform," The Wall Street Journal quoted the message as saying.
His resurfacing comes amid international criticism of the parliamentary race. Only 14 opposition candidates managed to take seats on the 508-seat Parliament, wiping Muslim Brotherhood candidates off the political map.
ElBaradei said this week he may consider joining forces with the Brotherhood to advocate political reform in Egypt.