The Qornet Shehwan Gathering is a mainly Christian coalition of politicians, intellectuals and businessmen who opposed the Syrian military presence in Lebanon.
For his part, the son and political heir of the slain Rafik al-Hariri has said the anti-Syrian opposition would sweep Lebanon's general elections and indicated that he could lead the government after the ballot.
Saad al-Hariri, taking over the mantle of his father, predicted on Tuesday the opposition will win 80 to 90 seats in the 128-member parliament.
In other developments, the head of the Lebanese army intelligence's wiretapping unit has been dismissed, meeting another demand of the opposition.
A senior military official, speaking on condition of anonymity, said on Tuesday that Colonel Ghassan Tufeili had been "placed at the disposal" of the army command and that Lieutenant-Colonel Sassine Mureib was expected to replace him.
"Placed at the disposal" is a term that means the official stepped aside without resigning.
Tufeili's name was among a list of pro-Syrian security officers whose removal had been a key demand of the opposition for negligence and cover-up in former prime minister Rafiq al-Hariri's killing.
Tufeili's removal came nearly two weeks before parliamentary elections were scheduled to begin.
Now only one general targeted by the opposition remains in his post, Brigadier-General Mustafa Hamdan, the commander of the Republican Guard Brigade, who is very close to President Emile Lahoud.