Greece is to seek a cash lifeline at an emergency meeting of eurozone finance ministers as it struggles to persuade its EU creditors to renegotiate its massive bailout deal.
Wednesday's talks follow the announcement by Alexis Tsipras, the prime minister, that he would not bow to German demands that his hard-left government first complete a pending loan agreement with the EU and the IMF.
"I want to repeat today, no matter how much [German Finance Minister Wolfgang] Schaeuble asks it, we are not going to ask to extend the bailout," Tsipras told lawmakers late on Tuesday ahead of a confidence vote which the government won by 162 votes to 137.
The EU had earlier warned Greece's new government to scale back its plans to revise the country's unpopular bailout if it wants to secure a six-and-a-half month lifeline that will enable it to meet pressing debt repayments in the coming months.
Greece wants the European Central Bank to hand over 1.9 billion euros ($2.2bn) in profits made from Greek state bonds.
Athens also wants ECB permission to issue up to 8 billion euros ($9bn) in short-term debt to meet its immediate financing needs, and to tap a European support fund originally created to prop up Greek banks.
The Greek government calls this a "bridge agreement" that will enable it to stay afloat until it can agree on a new four-year reform plan with its EU creditors.
European Economic Affairs Commissioner Pierre Moscovici said the existing bailout deal was "the anchor" on which discussions should be held, while Schaeuble ruled out any renegotiation of the agreement.
But Tsipras insisted: "As long as we have the people on our side we cannot be blackmailed or intimidated by anyone."
He added: "I am confident that our European peers will be responsive to our proposals. I cannot believe there are powers in Europe that want to lead a people to humiliation, to take vengeance and punish, when they know this can only harm us all."
Speaking during a G20 meeting in Istanbul, Moscovici said the Greek people's desire for change should not be "brushed aside" but Greece should also keep in mind voters in other European countries.
Schaeuble was even more emphatic, telling reporters in Istanbul that "it's over" if Greece does not want the final tranche of its multibillion euro aid programme on the current terms, according to Bloomberg.
Tsipras' legislative programme includes raising the minimum wage and ditching an unpopular property tax.
While welcomed by ordinary Greeks, the proposals have raised eyebrows on the international stage.