Tens of thousands of demonstrators marched through the center of Georgia's capital to the parliament building Tuesday to press their demand that President Mikhail Saakashvili step down.

The demonstrators, at least 60,000 strong, filled the national stadium in a two-hour rally before converging on the parliament in a daylong series of protests, their anger fueled by Saakashvili's handling of last year's disastrous war against Russia.

Opposition leaders chose a patriotic national holiday for the rallies, seeking to reinvigorate the protests they have been conducting almost daily in Tbilisi since April 9.

"Today the Georgian people have shown to the world and to themselves that they're ready to struggle to the very end," Nino Burdzhanadze, the highest-profile opposition politician, told the crowd at the stadium.

"You have frightened those who want to frighten you," she said to deafening cheers.

Demonstrators are angry with Saakashvili for leading Georgia into the war against Russia, in which Georgia lost territory and saw its military crushed and its towns bombed and large chunks of its land temporarily occupied by Russian troops. Russia then recognized independence of Georgia's breakaway provinces of South Ossetia and Abkhazia, but Georgia still considers them to be under Russian occupation.

The opposition also accuses Saakashvili of backtracking on democracy.

While the president still has a broad base of support in the former Soviet republic — which has experienced significant economic growth during his five years in office — opposition leaders hoped Tuesday's emotional demonstration would prove to be a tipping point.

Saakashvili has remained defiant, saying he would stay through his second term, which ends in 2013.

Tuesday's rally would have coincided with the annual military parade celebrating Georgia's short-lived independence before it was taken over by the Red Army in 1921. After decades of Soviet rule, independence was restored in 1991.

But the government canceled the parade, fearing clashes with the opposition.

No police were visible inside or outside the stadium at any point during Tuesday's rally.

Waving red-and-white Georgian flags, the demonstrators in the stadium cheered, sang the national anthem and burst into chants of "Sakartvelo! Sakartvelo!" — the name of the country in Georgian.

In a sign of the high-running emotions, Giorgy Gachechiladze — a famous singer and opposition figure — ran onto the soccer field and kneeled down in the center of a giant Georgian flag, pumping his fists.

Following the rally, religious leader Patriarch Ilia II was to address the crowd outside

Opposition supporters poured in from around the country, with some arriving in long convoys of cars. Overnight, hundreds of demonstrators carrying flags marched into Tbilisi in a torch-lit parade.

Saakashvili has offered to hold talks with opposition leaders on constitutional changes, but they have rejected the offer, saying they were only prepared to discuss his resignation.

For his part, Saakashvili gave a speech to young schoolchildren in Tbilisi and attended a memorial ceremony Tuesday honoring soldiers killed in last August's war. He also planned to visit the Black Sea city of Batumi, where he was to open a new street and visit local businesses.