A move by New Democracy chief Antonis Samaras to placate Greece’s lenders seems to have done little to calm the mood in his own party as some members continued to question the decision to provide the European Union and International Monetary Fund with written guarantees.

ND sources suggested that the party would have to brace for internal unrest following Samaras’s decision to send EU and IMF officials a letter confirming his commitment to Greece’s bailout packages.

“If we do not step on the brakes now then there will be more to come,” Failos Kranidiotis, an informal adviser to Samaras, told Skai TV. He suggested that EU officials’ statements about Greece not getting its 8-billion-euro loan tranche without a written guarantee from Samaras were “empty threats.”

Kranidiotis also suggested that PASOK may have been behind the demands for Samaras to write to EU officials in a bid to tarnish his image ahead of the early elections that are due to take place next year. A similar theory was put forward by Yiannis Manolis, another member of ND’s so-called “popular right” wing.

Manolis accused EU officials of asking Samaras to sign a “blank piece of paper” that would allow them to impose more austerity measures.

However, another outspoken member of the party, Athens MP Gerasimos Giakoumatos, said that the time for “bravado” was over. “New Democracy is a party that is doing its duty for the country,” he said.

Within PASOK, there was an attempt to douse the speculation about a possible leadership race. Three ministers - Costas Skandalidis, Miltiadis Papaioannou and Pavlos Geroulanos - ruled themselves out of the running for any contest and called for the party to concentrate on other matters.

Former Prime Minister George Papandreou has yet to clarify whether he will run, but Papaioannou said that he was certain the ex-premier would stand aside.