Tens of thousands of Venezuelans streamed through the streets of Caracas today to protest leftist president Hugo Chavez's second attempt to change the constitution to let him govern as long as he wins elections.
Opinion polls give a slight lead to Mr Chavez ahead of a February 15th vote on whether to allow the president and other politicians to run for reelection as many times as they like in South America's top oil exporter.
In 2007, voters rejected a similar proposal.
The march, under the slogan "no is no" and led by anti-government students and political parties who claim Mr Chavez will turn Venezuela into a version of communist Cuba, was the largest by the opposition in more than a year.
"This reform hides, as president Chavez himself has said, the start of what would be a country, a state with a Castro-communist system," said Manuel Rosales, a former opposition presidential candidate.
Mr Chavez, a vocal critic of the United States, is close friends with former Cuban leader Fidel Castro.
Some protesters wore shirts emblazoned with the phrase "I also want to be president" and many carried Venezuela's red, yellow and blue flag in the march that stretched from the edge of the city's largest slum into a wealthy business district.
Street vendors sold gas masks to protesters fearing a repeat of clashes with the police that have plagued smaller opposition marches in recent weeks.
Mr Chavez has nationalised industries and raised spending on health and welfare since he took office in 1999 but says he needs more time to build what he calls "21st Century socialism" in one of the principal oil suppliers to the United States.
He has amassed a great deal of power over the years, with most institutions run by his allies. Opponents say Mr Chavez is authoritarian and will turn people's homes and possessions over to the state.
He denies he will prohibit private property and points out the government still works in joint ventures with foreign oil companies.
Mr Chavez has won multiple elections in the last decade and survived a brief coup, a months-long shutdown of the vital oil industry and a recall referendum.
Despite massive street marches, the opposition has only recently made electoral gains against Mr Chavez, defeating the 2007 referendum and winning several key seats in state and city elections last year.
Apparently confident of victory, Mr Chavez has toned down his usually aggressive rhetoric against the opposition in recent days and on Friday said he welcomed the opposition march.
In comparison to the violence that often accompanies Venezuelan politics and despite a spate of scuffles between police and student protesters, campaigning from both sides has mainly been low key this year.
With only a small lead in polls before the referendum and fearful of a repeat of his 2007 defeat when millions of his supporters chose not to vote, Mr Chavez is pushing for heavy turnout by his backers at polling stations on February 15th.
Reuters