The opposition says it will not allow President Nicolas Maduro to change Venezuela's constitution "by act of force."
President Nicolas Maduro's plan for an elected assembly to draw up a new Venezuelan constitution was shot down by opposition parties on Sunday amid continuing violent anti-government protests.
The centre-right Democratic Unity Roundtable (MUD) formally rejected Maduro's plan for a "people's" assembly, saying they would not participate in a "fraudulent process."
"We cannot take part in a fraudulent process," former presidential candidate Henrique Capriles said, appearing at a news conference with other MUD leaders. "We have a constitution, and the government cannot repeal it by act of force.
Capriles, the opposition governor, ruled out their presence at a meeting on constitutional revision to be convened on Monday at the presidential palace. Instead, they plan to march towards the headquarters of the education ministry, in central Caracas, to present their argument.
Capriles maintains that Maduro, whose leadership has been rejected by seven of 10 Venezuelans according to some polls, is trying to avoid a general election, the main demand of the opposition protests since April 1.
The opposition has planned a series of protests demanding elections and an end to the "repression" of demonstrations, which have left 36 people dead and hundreds injured or jailed.
"Citizen assemblies would be held Tuesday to explain the 'flaws' in the constituent assembly," Stalin Gonzalez, an opposition lawmaker said.
On Wednesday, protests are scheduled to take place at the Supreme Court and other judicial offices around the country. Separate protests have also been planned for Thursday and Friday.
The demonstrations are yet to reach the centre of the capital, a stronghold of "Chavismo", the left-wing ideology created by Maduro's predecessor, Hugo Chavez.
On Sunday, the presidential panel guiding the constituent assembly process, led by Elias Jaua, met a group of youth leaders, informing them that the assembly would provide a path to peace and co-existence between the opposing sides.
Maduro's plan has drawn fierce criticism from many countries. The United States, Mexico, Brazil and Spain have said that any process to modify the constitution would require consensus.
While Chile is concerned about the worsening situation in Venezuela, Luis Almagro, secretary general of the Organisation of American States (OAS), has called the process "fraudulent."
But Maduro insists his hands are tied and he is dealing with an alleged "armed insurgency" seeking to oust him.
"There are two paths: either there is peace or there is fascism. Either we rewrite the constitution or we bow to interventionism," he told aides by phone late Sunday.