Demonstrators readied for what they hoped would be a show of strength in Beirut on Sunday - the 10th day of protests against Fouad Siniora's Western-backed government.
Protesters of all ages spilled into the streets waving the national flag, but the yellow flag of the Hezbollah guerrilla movement was also in evidence.
Hundreds of thousands joined the demonstrators who had been camping out in two squares in the city overnight.
Up to 20,000 troops were deployed on the streets and security around the government building was beefed up.
Cries urging Prime Minister Siniora to quit rang out as the rally led by Hezbollah and pro-Syrian allies got into its stride.
Hezbollah leader Sheikh Hassan Nasrallah has vowed his supporters will not leave the streets until a government of national unity is in place.
Some are saying Sunday's rally may be the biggest so far.