BERLIN — Despite bitter opposition in many quarters to the austerity-first policies Germany has imposed on Europe’s poorer nations, Chancellor Angela Merkel’s government has hung on to its role as champion of integration on the Continent through deft use of diplomacy and the country’s economic clout.

But in negotiating a new deal this week to bail out Greece, Germany displayed what many Europeans saw as a harder, more selfish edge, demanding painful measures from Athens and resisting any firm commitment to granting Greece relief from its crippling debt. And that perception was fueled on Thursday when the German finance minister, Wolfgang Schäuble, suggested that Greece would get its best shot at a substantial cut in its debt only if it was willing to give up membership in the European common currency.

Mr. Schäuble stressed that he was not pushing the Greeks to take any particular course and that in any case he was only talking about a temporary exit from the euro. But coming a day before German lawmakers are to give the go-ahead to negotiate the details of the bailout package for Athens, his remarks were evidence of a continuing deep ambivalence among conservatives in Germany about the costs of keeping Greece in the currency zone and a greater willingness to question whether the goal of “ever-closer union” in Europe should be reassessed.

Many in Germany still support the idea that keeping Greece in the eurozone is important for the future of the European Union, and German lawmakers are expected to support the new bailout plan, agreed to by European leaders early Monday after a contentious weekend of negotiations, when it comes up for a vote in Berlin on Friday.