A senior parliamentary ally of German Chancellor Angela Merkel believes a deal with Athens on a new multi-billion-euro bailout is some way from completion, with a number of points still to be clarified.
"There are a lot of questions that remain open," Ralph Brinkhaus, deputy parliamentary floor leader for Merkel's conservatives, told Deutschlandfunk radio on Monday.
Greece's finance and economy ministers were locked in negotiations with representatives of creditors that stretched until the early hours of Monday.
A Greek official said Greece hoped to conclude negotiations with international creditors by early Tuesday at the latest.
Asked whether Germany favored 20 billion euros ($21.9 billion) being handed to Greece in a first tranche of aid, rather than 30-35 billion as favored by the EU and the International Monetary Fund, Brinkhaus replied:
"The more money is handed out in one stroke, the less leverage one has to stop payments if the reform process in Greece does not pan out as planned and as promised.
"A lot of trust has been lost in recent months," he said, adding that aid should only be provided in return for Greece delivering reforms.