Cuban President Miguel Diaz-Canel and his wife, Lis Cuesta, vote in the referendum for the new Cuban constitution in Havana on February 24.
CNN  — 

Cubans have overwhelmingly voted to approve a new constitution that enshrines the one-party system and ushers in a series of economic and social changes, according to government officials.

Almost 87% of the 7.8 million people who participated in the historic referendum on Sunday voted to ratify the new constitution, according to preliminary results.

More than 700,000 Cubans – or 9% of those who voted – marked their ballot against the constitution, a rare sign of widespread dissent on the communist-run island. Cuban officials heavily pushed voters to approve the constitution and censured or stifled public campaigning against the referendum. Just over 4% of the ballots were left blank or were invalid, officials said at a news conference in Havana on Monday.

Authorities said the results would be official once the final count is done.

The updated constitution was crafted with the input of ordinary Cubans, through thousands of meetings between government officials and citizens to suggest modifications to the constitution.

The new document replaces the 1976 Soviet-era charter enacted under Fidel Castro. It protects private property and foreign investment, and for the first time places two five-year terms on the office of the presidency.

However, following a backlash by conservative religious groups, the government backed off from language that would have legalized same-sex marriage in the constitution.

A matter of patriotism

The referendum was widely seen as a vote on whether or not socialism had a future in Cuba.

Earlier this week, US President Donald Trump claimed that “socialism is dying” and described Cuba as a “captive nation.” But Cuban officials framed voting yes to the constitution as a matter of patriotism.

Across the island, government supporters placed signs on buildings, doorways and school buses urging people to vote for the constitution. There were few – if any – public displays supporting a “no” vote. Dissident complained they had been blocked from campaigning against the constitution.

In one government-produced video released on social media ahead of the vote, former Cuban spy and onetime US prisoner Gerardo Hernandez raises the stakes.

“I will vote ‘yes’ because there are two groups, the ‘yes’ and the ‘no’,” he said. “The ones calling us to vote ‘no’ are the traitorous enemies of Cuba.”

On his official Twitter account, Cuban President Miguel Diaz-Canel said a “yes” vote was “a mobilization for peace and against imperial intervention in Latin America.”

Under the new constitution, the Communist party is still the only political party allowed in Cuba, and it remains the guiding force for all government policy.

CNN’s Patrick Oppmann in Havana and Jaide Garcia in Atlanta contributed reporting.