Eurozone finance ministers dismissed a Greek request for a one-month bailout extension, increasing the chances of a default that could see the country exit the monetary union, the Wall Street Journal reported Saturday. The ministers now will begin discussing in earnest the consequences of such a default, a day after Greek Prime Minister Alexis Tsipras said he would put the terms of the austerity measures demanded by creditors to a national vote.

The announcement almost guarantees Greece will miss a June 30 deadline to make a $1.7 billion payment to the International Monetary Fund, which would threaten the government’s solvency and could lead to a collapse of the country’s banking system.

Eurozone finance ministers said they were taken aback by Tsipras’ surprise announcement of a referendum, the Journal reported. Jeroen Dijsselbloem, the Dutch finance minister who led the Greek bailout talks Saturday, called it “a sad decision for Greece because it has closed the door for further talks.” Wolfgang Schauble, the German finance minister, also said the announcement effectively ends further talks and moves the focus on how to deal with a Greek default.

“Plan B becomes Plan A,” Alexander Stubb, the Finnish finance minister, told reporters as rescue funding for Greece is now on hold. 

Meanwhile, Greeks have begun to drain ATMs across the country, while banks started limiting withdrawals, according to Bloomberg Business.

The call by Tspiras’ leftist government call for a July 5 referendum will likely lead to public rejection of further austerity measures proposed by Greece’s creditors. He called the rescue terms an assault on democracy.

“After five months of hard negotiations, our partners, unfortunately, ended up making a proposal that was an ultimatum towards Greek democracy and the Greek people, an ultimatum at odds with the founding principles and values of Europe, the values of our common European construction,” Tspiras said in a national address, according to the Guardian newspaper in the U.K.

The European Central Bank has been propping up Greek banks, but the ECB is prohibited by its own rules from continuing to support them with crucial funding indefinitely under the current circumstances. However, the ECB would like to avoid being the catalyst for a collapse of the Greek banking system.

“The ECB cannot be seen to be an agent of economic collapse in Greece,” an anonymous source close to the central bank told BBC News.