Egypt's largest opposition grouping is reaching out to members of Hosni Mubarak's ruling party as it gears up for a protest campaign against the current Islamist president.

Members of the ousted autocrat's National Democratic Party have been derided as "feloul" or the "remnants" by both current President Mohammed Morsi and the liberal groups that are his most active opposition. A yet-untested "political isolation" clause in the new constitution may ban senior officials in the now-dissolved party from top posts.

But opposition leader Mohamed ElBaradei told a Cairo conference on Saturday, "I can't isolate millions of Egyptian people because they were part of the National Democratic Party."

ElBaradei made his call in advance of mass protests planned by the opposition for June 30 to demand Morsi's ouster.