In an unexpected move Monday in front of the country's parliament, Prime Minister Omar Karami gave his resignation, effectively terminating the rule of the current Syrian-backed government.
The announcement was aired live on television and was greeted with jubilation from tens of thousands of Lebanese protesters who gathered just a few hundred yards from the parliament building.
"The government didn't fall now. It fell Monday when you all gathered here. You are the ones who are going to make Lebanon independent," Akram Shehayeb, an opposition member of parliament, told the throng of flag-waving protesters.
The resignation was the most dramatic moment yet in the series of protests and political maneuvers since the assassination of former Prime Minister Rafik Hariri.
Some 25,000 protesters gathered in the city center Monday in defiance of a government ban on demonstrations, the latest rally against Syrian dominance following the assassination of Mr. Hariri.
The demonstration came as the Lebanese parliament debated over who was responsible for the assassination of Hariri, who died in a bomb blast two weeks ago. Many Lebanese accuse Syria of murdering Hariri because of his alliance with the Lebanese groups that oppose their dominance here.
Although the resignation is a victory for Lebanese opposition groups, it does not spell the end of Syrian dominance over their tiny neighbor.
"The battle is long, and this is the first step, this is the battle for freedom, sovereignty and independence," said opposition lawmaker Ghattas Khouri.
Hariri's flower-bedecked grave beside the Al-Amine mosque in Martyrs' Square has become the focal point for the protests with hundreds of mourners maintaining a constant vigil. "We will stay here until there is freedom," says Elie Absi, a demonstrator.
Opposition groups have tapped into the public outrage at Hariri's murder to launch a peaceful campaign to undermine Syria's grip on Lebanon and force it to withdraw its estimated 14,000 troops. Demonstrators are taking their cue from other recent demonstrations in other parts of the world, such as the rallies in Ukraine last November that arose from a rigged election for prime minister. The "Orange Revolution" there resulted in a new election and the eventual victory of a Western-leaning candidate.
Just as Ukrainian students formed a tent city in Kiev and adopted the orange of the opposition's campaign, on a grassy knoll surrounding the Martyrs' Monument, 100 yards from Hariri's grave, some 150 young Lebanese have erected tents and vowed to remain until Syria withdraws its troops. Protesters are wearing thousands of red and white scarves, the colors of Lebanon's flag, which have become the motif of their campaign.
"The Syrians cannot ignore all the people coming out here every day," says Rene Klat during Monday's rally. "This will definitely make the Syrians leave. We don't need or want weapons to achieve our independence."
So far, the protests have remained peaceful. Indeed, the most striking element of the demonstrations is the diverse array of participants, from students to bankers. They also cross sectarian lines, as well, with Christian Maronites rubbing shoulders with Sunni Muslims and Druze. "We have removed the mask of fear. We are not afraid anymore," says Fadi Romanos, who runs an insurance company in Beirut.
It took Sami Nasrallah over three hours to reach Martyrs' Square from his village of Qaa in the northern Bekaa Valley. "This is the real Lebanese spirit," he says, gesturing at the cheering throng.
But it takes more than popular sentiment to maintain the demonstrations. Working behind the scenes are hundreds of young activists representing the main opposition groups. They meet several times each day to plan their next moves.
"We will continue these demonstrations every day until we reach our goal. The goal of all Lebanese is a free and sovereign country," says Michel de Chadarevian, an official with the Free Patriotic Front, a political movement headed by Michel Aoun, a former Lebanese Army commander who has lived in exile in Paris since leading a failed uprising against Syrian forces in Lebanon in 1990.
Activists from Hariri's Tayyar al-Mustaqbal (Tide of the Future) movement have been churning out posters of the slain former premier, along with stickers shaped as a black ribbon with the word "Truth" written in English. Other groups are printing banners with "Independence '05."
Activists are using text messaging over mobile phones to spread the word of any last-minute changes to demonstrations and to subvert roadblocks and security forces. This technique was used successfully in the Philippines in 2001 to quickly organize the mass demonstrations that brought down President Joseph Estrada.
On Sunday night, Lebanese Interior Minister Suleiman Frangieh announced a ban on all demonstrations. His decision came after government supporters said they would hold a rally at the same time and place as the opposition gathering, prompting concerns that the encounter could turn violent.
While government loyalists observed the ban, the opposition supporters defied the presence of hundreds of troops and riot police to gather in Martyrs' Square.
Throughout the morning, thousands more demonstrators converged on the city center, turning nearby streets into a surging sea of red and white flags.
The streets around the parliament building were sealed tight; only politicians attending the parliamentary debate were allowed through. Several thousand protesters began building up at one of the main roads leading to the square as soldiers and police stood behind coils of barbed wire. Protesters sang the national anthem and joked with soldiers. Others threw rose petals over the soldiers and called out "the Army are our brothers and stand by us and not against us."
• Wire material was used in this report.