The European Commission said it was mediating between Spain, Portugal and Greece after Madrid and Lisbon complained to the EU executive about accusations by Greek left-wing Prime Minister Alexis Tsipras' that they were conspiring against Athens.
Tspiras accused Spain and Portugal of leading a conservative conspiracy to topple his anti-austerity government because they feared the rise of the left in their own countries.
Spain's centre-right prime minister, Mariano Rajoy, hit back on Sunday saying his country, which was struggling with its own financial problems, had lent billions of euros to help Greece.
He said Spain was not responsible «for the frustration generated by the radical Greek left that promised the Greeks something it couldn't deliver on."
Portugal and Greece complained to the European Commission, asking the EU executive arm to comment on the Greek remarks.
"The complaint, including a request to comment, from the Spanish and Portuguese governments has been communicated to the Commission over the weekend and this is regarding the statement of Prime Minister Tsipras,» a Commission spokeswoman told the daily news briefing.
"We are now in close contact with all actors involved ... in order to ensure there is unity among EU member states and especially among the EU states of the euro zone,» she said.