By Will Grant
BBC News, Caracas
Critics say Venezuelan President Hugo Chavez shouldn't serve another term
In what is the 15th vote since Venezuela's President Hugo Chavez came to office, there is arguably more at stake this time than in any of the previous 14 votes.
After 10 years in power, the Bolivarian revolution is at a crossroads.
The Venezuelan people will decide whether to grant Mr Chavez the right to stand again for office, or oblige him to stand down in 2012, at the end of his current term.
The president says he needs the right of unlimited re-election in order to take Venezuela into what he calls the "third phase" of the 21st Century socialist revolution.
His opponents say the entire measure is an attempt to concentrate the powers of the executive into his hands for the next 20 or 30 years.
For many Venezuelans, these are familiar arguments. It was not so long ago that a similar constitutional referendum was held.
In December 2007, a package of 69 reforms, ranging from lowering the voting age to removing the limit on the number of times the president can stand for office, was put in front of the Venezuelan people. The plan was narrowly rejected.
The opposition says that as this question has been voted on once during this presidential term, Sunday's referendum is unconstitutional. "No means NO!" is their campaign slogan.
But the government denies the charge. It has said Sunday's vote is on a specific change to a single article in the constitution, not a wholesale reform.
Secondly they argue that this time around, the question of unlimited re-election has been extended to local mayors and state governors and as such, it is a different question to a year ago.
For one of the Socialist Party's members of the national assembly, Augusto Montiel, this 15th vote underscores the strength of the electoral process in Venezuela.
"The point here is to expand the rights - the democratic rights and political rights - of the people in Venezuela," he said.
"We think that people should be able to vote for somebody they like if that person decides to run again for power."
For other analysts, the very fact the vote is back on the table does not bode well for democracy in Venezuela.
"That Mr Chavez speaks of himself as indispensible and as practically identical with the cause of the people indicates that he is a dictatorial personality," says Demetrio Boersner, a former Venezuelan ambassador.
Hugo Chavez remains popular after ten years in power
"The insistence of one man to be able to be indefinitely re-elected having already accumulated almost total personal power, dominating as he does the executive, the legislative and the judicial branches of government, well that's a very depressing idea."
This has been a short campaign. Mr Chavez said he would seek a change in the constitution soon after local elections in November, when the opposition made key gains in a number of areas previously considered Chavez heartlands, such as the Caracas shanty town of Petare.
Mr Chavez said the vote would happen quickly because he "didn't want to spend 2009 arguing about the issue".
But some economists think there is a more pressing reason for a snap referendum: the fall in the price of a barrel of Venezuelan crude oil.
"The whole so-called socialism, which means state spending for the social projects of Mr Chavez, has not been based on higher general productivity in the country but simply on the extremely high price of oil," says Mr Boersner.
As such, he says the government's popular social development programmes are being affected and that Mr Chavez will lose a section of his core support at the polls on the 15 February.
"The workers and the poor of Venezuela, the low-income classes, are more and more turning their backs on Chavez, they are angry, they feel deceived," he said.
Youth vote 'crucial'
Many ordinary people in Venezuela are tired of the radical politics which have dominated their country for the past 10 years.
After all the rhetoric, there are still major problems in the Opec nation, particularly in terms of violent crime and rising inflation.
Yet President Chavez continues to regularly poll above 50% in the personal popularity ratings, and his supporters are out in large numbers every day canvassing for the "Yes" vote.
In 2007, the student protest vote was key in defeating the measure on presidential re-election. This time around too, the youth vote is again set to be crucial.
One such young voter is 18-year-old Henry Sabello, who will be casting his ballot for the first time in a national vote on Sunday.
Henry is a member of a group called "Tiuna, el Fuerte", a community group funded by government money which works with young people from the local shanty towns to encourage them away from crime.
Henry, who left his gang-member lifestyle to work for the NGO, has no doubt that Mr Chavez deserves at least another term in office.
"The wealthy keep the poor people down. But Chavez has helped the poor and the people in the shanty towns a lot. He's helped me too," he said.
"It's the first time we've had a president like this, and he deserves our vote, because he's been important to many people. I know," he adds, nodding towards his neighbourhood, "because I've seen it and I've lived it."
Manuel Figuredo is also 18 and he too will be casting his referendum ballot for the first time on Sunday.
But that's where the similarities between the two young men end.
There is a vociferous anti-Chavez campaign
At a "No" campaign rally in the centre of the capital, Manuel spoke of his hopes of one day becoming a politician. He says that granting the president new constitutional powers would affect the opportunities for young people like him.
"It would be really unfair to change the constitution now because although it seems like people would still be able to choose their leader, there'd be no alternation of power," he argued.
"If you look at the countries which allow re-election, such as Cuba, it's very dangerous because although leaders may start out as popular, they soon get used to power and they forget that it was the people who gave them that power."
Voters like Manuel consider that 10 years in office, rising to 14 by the end of his second term, is enough for one leader.
But for the Socialist Party member, Augusto Montiel, there is only one likely outcome on Sunday: "The social projects developed under this government have helped more than 18 million people who never before received that help.
"The truth of the matter is that the great majority of Venezuelans, the poor people, are very happy with President Chavez as their leader and will accept him again as a candidate for president, as they will accept any governor who does a good job."