Top politicians in Berlin urged Athens to hurry up and implement reforms before the last tranche of a 240 billion euro ($270 billion) aid package could flow into the country and the possibility of a third aid package could be discussed.

Greece is running out of cash and talks with Brussels have been deadlocked over the country's refusal to cut wages and pensions and liberalize the labor market.

"A third tranche of aid for Athens is possible only when reforms are implemented. We cannot simply send money there," the German Economy Minister Sigmar Gabriel told the "Bild am Sonntag" weekly. He also admitted that a referendum on the aid package could be a possibility, as suggested by German Finance Minister Wolfgang Schäuble earlier this week.

The Christian Democratic Union's (CDU) parliamentary leader, Volker Kauder, also pointed at Greece's unwillingness to cooperate and said Athens needed to demonstrate it was willing to implement what had been discussed.

German Finance Minister Wolfgang Schäuble has been openly critical about Athens' unwillingness to implement changes

However, Kauder argued it was too early to consider a third package for Greece, since the EU and Greece's international lenders were yet to release the last installment of the current economic package.

Grexit could be 'politically explosive'

Greece's Prime Minister Alexis Tsipras has been embroiled in extensive negotiations with the European Union, the International Monetary Fund (IMF) and the European Central Bank (ECB) over the last three months. The lenders have been insistent that Athens implement important changes in its economic setup so that the final 7.2-billion euros ($8.2 billion) of the bailout can be released.

Germany, the European Union and the IMF's experts have been in touch over the weekend, a spokeswoman of the European Commission confirmed with German news agency dpa. The EU and Germany, both have rejected the possibility of a Grexit, with the Gabriel saying that Greece's exit from the eurozone would be "politically explosive."

"When the first country leaves, the rest of the world will look at Europe differently," Gabriel said. "No one would have any more trust in Europe, if we break away from each other during our first crisis."

mg/sms (dpa, Reuters)