More than a million Venezuelans poured into the streets of the capital to demand the resignation of President Hugo Chavez.
Protesters yesterday filled bridges, overpasses and parks along Caracas's busiest highway, carrying giant Venezuelan flags, blowing whistles and chanting anti-Chavez slogans.
Caracas's Fire Chief Mr Rodolfo Briseno said more than one million people were demonstrating in what he called "the biggest march we've seen in recent times".
Meanwhile, government officials summoned Mr Chavez supporters to an unannounced "Christmas celebration" where several thousand people danced and clapped their hands to traditional Christmas music.
The pro-Chavez demonstration was on the path the opposition rally would need to take to reach the presidential palace. A march on the palace in April led to violence that killed 19 people and sparked a coup that ousted Mr Chavez for two days.
But opposition leader Mr Carlos Ortega said he would not urge the marchers to move on the palace, saying that "would be irresponsible at this point".
"This response should bring the head of state to make the decision he needs to make about Venezuela's crisis - and that is none other than to leave, quit, so Venezuela can restore confidence, peace and calm," he said.
Protesters marched with their children, and their dogs. Many followed the march route on bicycles, skateboards and motorcycles.
From a stage under a starry sky, musicians played Venezuelan folk music, dissident military officers fired up the crowd and comedians mocked Mr Chavez's close friendship with Cuban President Fidel Castro.
"Chavez has two jobs: president of the republic and first lady of Cuba," comedian Carlos Donoso said, to roars of laughter from the crowd.
The government, the opposition and international mediators have warned that riots could break out any day as the 13-day-old strike makes food, cash and transportation increasingly scarce - and makes Venezuelans more polarised.
Dozens of Chavez supporters protested outside a closed bank yesterday, demanding it open its doors and cash their cheques as 20 police officers in riot gear blocked them from breaking in.
The strike has crippled Venezuela's oil industry - the world's fifth largest - rattling international markets and its chief petroleum customer, the US.
AP