Greek finance minister Yanis Varoufakis has accused his nations' creditors of "terrorism", less than 24 hours before a critical bailout vote which could decide if they remain part of the EU.
On Sunday 5 July Greeks will vote on whether to accept or reject conditions sought by international creditors to extend a lending lifeline.
Citizens will head to the polls to vote for or against an EU bailout after a previous bailout programme with the European Commission, International Monetary Fund (IMF) and European Central Bank (ECB) expired on Tuesday.
In an interview with the Spanish newspaper, El Mundo, Yanis Varoufakis, said that the EU will lose a trillion euros if Greece leaves the union.
"If Greece crashes, a trillion euros (the equivalent of Spain's GDP) will be lost. It's too much money and I don't believe Europe could allow it," said Varoufakis. "Why have they forced us to close the banks? To frighten people. And when it's about spreading terror, that is known as terrorism."
The Greek government is led by an anti-austerity party which came to power in January that is actively urging Greek citizens to vote "no" to the bailout in Sunday's referendum.
But their oppositions warn that this would see Greece removed from the eurozone.
On Friday night, huge rallies were held by both sides in the run-up to the referendum with opinion polls indicating an even split.
Addressing a crowd of over 50,000 in central Athens, left-wing Prime Minister Alexis Tsipras urged them to snub the deal.
In the past week many banks have been shut, with limits imposed on cash withdrawals, bank transfers frozen, and Greek citizens facing a €60 limit on ATM cash withdraws.
Banks in the country report that they have just €1bn available until Monday.
President of Athens Chamber of Commerce, Constantine Michalos has warned that unless a deal is struck soon it is unlikely banks will open on Tuesday.