Socialist PASOK leader Evangelos Venizelos on Thursday became the third political leader to receive a presidential mandate to form a government after efforts by his political rivals failed to yield a compromise.

In a televised meeting with President Karolos Papoulias, Venizelos pledged to «explore all possibilities» in his bid to form a unity government even as serious doubts lingered about his ability to broker a deal with his political rivals.

Venizelos told reporters outside the presidential mansion that he would approach all parties in favor of keeping Greece in the eurozone, starting with conservative New Democracy, the Coalition of the Radical Left (SYRIZA) and the Democratic Left, for talks. «Things are not easy and I am not saying I am optimistic but I am determined to serve the national interest,» he said.

In a speech earlier to his party's parliamentary group, Venizelos said that voters had punished PASOK, perceiving it as responsible for the crisis. He also accused SYRIZA leader Alexis Tsipras of misrepresenting his position on forming a coalition, noting that he did not want a «transitional government» that would freeze Greece's reform process but a unity coalition. Venizelos was responding to the leftist's charge that he and conservative ND leader Antonis Samaras had only pretended to seek a solution to the political deadlock.

Earlier in the day, Tsipras returned to Papoulias the mandate he was given to form a government. Tsipras told Papoulias that he had «exhausted every possibility and scope for creating a government compatible with the popular mandate.» The president expressed his «sorrow» at Tsipras' inability to form a coalition and added, in comments reported later by state television Net, that he was uncertain how long it would take to form a new government, referring to a «Gordian Knot.»

In a related development, Communist Party (KKE) leader Aleka Papariga told a press conference that the only way out of the current political deadlock were fresh elections.

The most likely date for a second round of polls, which will be called in the event that Venizelos fails to form a coalition and Papoulias fails to broker one subsequently, is June 17.