Jassim Hussein of al-Wefaq, the largest opposition party, told the Voice of America, "I think opposition groups have to work out strategies among themselves and they also have to meet with the Feb. 14 movement. ... I think we're talking about days before any announcement of the start of dialogue."
The gulf state's unrest began with a "Day of Rage" on Feb. 14.
Al-Wefaq, struggling to keep up with young demonstrators' demands, pulled out of Parliament last week.
"I don't think the regime is willing to meet most of our demands. But even if it does, I am not sure it will be enough to get the youth off the street," Hussein told the Christian Science Monitor.
Crown Prince Salman bin Hamad al-Khalifa has called for a national dialogue.
Protesters recaptured Manama's Pearl Roundabout Saturday and re-established their tent camp.
Inspired by protests in Tunisia and Egypt, Bahrain's 70-percent Shiite majority is demanding a greater voice in the government.