Athens---Greek Prime Minister Alexis Tsipras is facing a showdown both with international creditors and dissenters in his party as his government toils to reach a default-saving loan deal in less than a month.
Athens this week unexpectedly opted to bundle four IMF loan payments into a single one due by the end of June, giving the 40-year-old premier just weeks to reach an agreement with creditors that sceptics in his hard-left party could accept.
Greece and its international creditors have wrangled for weeks as they try to hammer out a reform plan that would unlock the final 7.2 billion euros ($8 billion) in bailout funds for Athens.
With the clock ticking on a deal to prevent a Greek debt default, German Chancellor Angela Merkel, French President Francois Hollande and Tsipras spoke by phone on Saturday.
"They took stock of the situation to help move forward the negotiations between Greece and the three (creditor) institutions," a French diplomatic source said.
The three-way talks came on the eve of a Group of Seven summit in Germany that looks set to be overshadowed by the Greek drama, even though Tsipras himself is not attending the high-level gathering.
In a sign of growing tensions with Athens, European Commission President Jean-Claude Juncker snubbed a request from Tsipras to talk on the phone earlier Saturday, a day after the radical leftist leader labelled the latest creditor proposals as "absurd".
"I can confirm that there was a request for a call... No phone call today," a commission spokesperson said.
Tsipras's outburst on Friday had already been coldly received in some European circles, with one source saying it was tantamount to Tsipras "spitting in the soup."
"There is a feeling of fatigue and disappointment among the creditors," the European source told AFP, noting that the Greek PM's tone was "very aggressive".
However, with Tsipras under pressure from hard-left cynics within his party, another source involved in the talks dismissed his harsh words as "rhetorical".
Athens this week withheld a 300-million-euro loan repayment to the International Monetary Fund, opting instead to group four scheduled tranches into a single payment at the end of the month.
This means Greece must now find 1.6 billion euros in three weeks -- funds it is unlikely to muster without a deal with its EU-IMF creditors.
This, in turn, is unlikely given the creditor demands, said Greek Energy Minister Panagiotis Lafazanis, the ruling party's top EU sceptic.
"It is obvious that given their demands, there can be no convergence between our government and the institutions," Lafazanis, who is believed to influence a third of the party, told The Telegraph.
AFP