'Door to dialogue open,' Merkel says

Addressing the lower house of parliament, the Bundestag, on Wednesday, Merkel stressed that the Greek people should be politicians' primary consideration during all future talks.

"We have some turbulent days behind us, but there are still many turbulent days in store for Greece," Merkel said in her opening remarks. "We have to remember the people of Greece. They're a proud people and the will have many difficult days to overcome. But the door to dialogue with Greece remains open. We owe this to the Greek people."

Finance Minister Wolfgang Schäuble agreed with that sentiment, saying that ordinary people were most affected by the debates and disagreements of recent weeks. However, Germany's hawkish lead negotiator also warned that further talks were redundant given the current uncertainties, especially with regard to Sunday's planned referendum.

"Greece was on the right path in 2014," Schäuble said. "But since this government came to power, Greece has reneged on its agreement. It is unclear whether they will or will not hold a referendum. You cannot expect us to have talks with them amid such a situation."

Chancellor Merkel detailed how Greece had failed to meet its International Monetary Fund (IMF) deadline overnight. While Athens had the right to call a referendum on the terms of continued European loans, Merkel said, the other 18 eurozone countries also had the right to take a strong stance against this move.

"We will wait for the result of the referendum. Before that, we won't be able to discuss any further aid packages," Merkel said.

Opposition accuses Merkel of wanting to oust Syriza

However, opposition leader Gregor Gysi of the left-wing party "Die Linke" criticized Merkel's position, saying that her true target was to see the current Syriza government in Greece collapse after the referendum.

"That is not fair. France and Austria are willing to talk to Greece ahead of Sunday, but you are revealing your true colors by insisting on waiting until Sunday," Gysi said. Gysi also warned the plenary session that the eurozone might ultimately collapse altogether as a result of a Grexit, while attracting a great deal of heckling.

"If there's a chain reaction after a Grexit leading to the collapse of the euro, we will only have ourselves to blame," he pleaded, adding that even the European Union as a whole might suffer despite its best intentions.

Merkel: 'Europe stronger than five years ago'

Merkel disagreed, however, insisting that Europe remained strong, and even saying that the European Union was much stronger than it was "five years ago, when the crisis started in Greece."

"Everyone has to be happy to enter a compromise," Merkel said."This applies to Germany and France as much as it applies to Greece. If Europe lost its ability to find a compromise, Europe would be lost. But Europe's future is not at stake. This union of values remains strong."

Gysi demands a European Union based on social justice

However, Gregor Gysi had a different idea about the values that should be considered moving forward, lashing out at the chancellor for not living up to what was expected of her.

"We need a different kind of Europe, where it is clearly defined that social justice is the highest of all values," he said. "Mrs. Merkel, you have the opportunity to go down in history as either the savior of the European idea or as its destroyer."

In his closing remarks, Finance Minister Schäuble instead focused on the Greek leadership as a potential "destroyer" of the European idea: "we have to establish a basis, which cannot be destroyed by anyone."