German Chancellor Angela Merkel

Greece's Finance Minister Yanis Varoufakis said German Chancellor Angela Merkel must make a clear decision at a eurozone summit Monday on whether to negotiate a rescue deal with Athens or heed populist calls to jettison the debt-wracked country.

Merkel can "enter into an honourable agreement with a government, which has rejected the 'rescue package' and is seeking a negociated solution, or follow the calls from (those in) her government who want her to throw overboard the only Greek government which has been faithful to its principles and which is able to take the Greek people on the road to reform," said Varoufakis.