Activists presented the signatures of over 11,000 Cubans to the National Assembly on Friday in a push to reform the country's Socialist system and ensure the civil liberties of citizens.
The campaign, known as Project Varela, proposes a referendum that would allow Cubans to decide whether rights similar to those in the U.S. Bill of Rights should be guaranteed. The project is named after Felix Varela, a Cuban independence hero and Roman Catholic priest.
"The world should know that we Cubans are traveling our own road to improve our society," campaign coordinator Oswaldo Paya said. "Whoever wants to express solidarity with Cuba, and respect the self-determination of Cubans, should support this demand for a popular vote."
One likely supporter of the movement is former President Carter, who is scheduled to arrive on Sunday for a five-day visit. The State Department has asked Carter to tell Castro that it's time for Cuba to become a democracy, department spokesman Richard Boucher said Friday.
Carter is scheduled to meet with activists on Thursday to discuss human rights.
"The Varela Project is the most important issue former President Jimmy Carter can possibly deal with on his trip to Cuba this week," said Jorge Mas Santos, chairman of the Cuban American National Foundation, a powerful Miami-based lobbying group.
Campaign members collected more than 20,000 signatures in support of the measure; of those, 11,020 were verified as legal voters and delivered. Activists went to each person's home to verify that their identity and documentation matched that on the petition.
Cuba's constitution says the Assembly should schedule a referendum when more than 10,000 signatures of legal voters are collected.
The government has yet to respond to the petition, but in April, Foreign Minister Felipe Perez Roque accused the movement's organizers of being paid by the U.S. and doubted the movement would succeed. Paya denies the allegation, saying funding for the movement came only from within Cuba.
Paya accused the government of sending agents to harass campaign workers. In addition, Paya said those agents seized thousands of signatures, but that campaign workers had gone out to collect more.
Despite the alleged government interference, another organizer of the campaign says its purpose is not to remove Castro.
"Project Varela does not say that the government should go, but rather that it make some modernizing changes," said Elizardo Sanchez, who also coordinated the campaign. "The important thing about Project Varela is the mobilization of Cuban society ... the rupture of the culture of fear."
The Associated Press contributed to this report.