Final opinion polls released at the end of Greece's referendum showed the "no" vote leading by a small margin in the July 5 vote on a bailout proposal from the country's international creditors.
No exit polls have been taken, but three opinion polls by GPO, Metron Analysis, and MRB all showed the "no" camp ahead by a margin of three points.
The polls were released after voting ended on the evening of July 5 because of a ban on the publication of polls on the day before a vote is held.
Ahead of the vote, there were signs the nation's 10 million voters were evenly divided over the ballot measure asking them to accept a new austerity plan offered by European leaders or reject it in a move that might push Greece out of the eurozone.
The referendum was called by left-wing Prime Minister Alexis Tsipras, who urged voters to vote against "fear" and "terrorism" by rejecting the prescription of European leaders after six years of recession.
But fear of losing Greece's place in the eurozone and European Union appeared to be driving many voters to say "yes" to the demands for fiscal reforms.
Tsipras said he was "optimistic" about the outcome of the referendum as he cast his ballot at a polling station in the Kypseli neighborhood of central Athens.
"Many may ignore the will of a government but not the will of the people," he said. "I am confident that tomorrow we will open a way for all the people
The 40-year-old Tsipras is gambling the future of his government on the hastily called referendum, insisting a "no" vote will strengthen his hand to negotiate a third bailout with European leaders despite their warnings to the contrary.
If he loses, Tsipras has vowed he would step aside and allow a new government to carry out the tough spending cuts and tax increases the European Union is demanding in exchange for new loans and a writedown of Greece's $300 billion in debts.
An angry and exhausted public, after years of crippling recession, was forced to suffer in the past week under capital controls imposed to prevent the collapse of the nation's banking system after Tsipras broke off negotiations with European leaders.
"There is an atmosphere of fear. You can just feel it," said Sarafianos Giorgos, a 60-year-old teacher in Athens, who says he will vote in favor of the European leaders' plans.
Evgenia Bouzala, a Greek born in Germany, said she was considering shutting down her olive oil export business because of the financial turmoil.
"I don't think we can keep going. Look at what happened in the last three days. Imagine if that lasts another six months," she said, referring to the closure of banks, limits on cash withdrawals, shutdown of credit lines, and other financial obstacles Greeks faced during the week.
"A 'yes' vote would bring a caretaker government and that would probably be better... We have to start over," Bouzala said.
Rallies for both campaigns were also held in 10 Greek cities and Athens amid high drama and intense rhetoric.
A series of polls published at the end of a frantic weeklong campaign showed the two sides in a dead heat, with an incremental lead of the "yes" vote, well within the margin of error.
They also showed an overwhelming majority of people — about 75 percent — want Greece to remain in the euro currency zone. That sentiment lends support for the "yes" side of the ballot since European leaders have warned that a "no" vote is a vote to exit the eurozone.
But many voters confessed they are confused, and the nation's voters won't get any help from the complicated question posed on the ballot. It asks them to approve or reject a two-part plan "submitted by the European Commission, the European Central Bank and the International Monetary Fund to the Eurogroup on 25 June."
"People don't even understand the question," Athens Mayor George Kaminis told supporters at the "yes" rally.
"We have been dragged into a pointless referendum that is dividing the people and hurting the country."
With reporting by AP, dpa, and AFP