Athens, Greece (CNN) -- Greek politicians have been unable to form a new government in their economically embattled land late Friday, and the president might have to step in to breach the impasse. Socialist PASOK leader Evangelos Venizelos met with Antonis Samaras, head of the center-right New Democracy party, and Alexis Tsipras of the leftist Syriza party and failed to forge a deal, the parties reported. Venizelos was the third Greek politician since Sunday tasked with forming a new government. Samaras and Tsipras had tried and already failed to organize a government. Venizelos is to meet with President Karolos Papoulias and tell him he can't form a coalition, government officials said. Papoulias will call the party leaders and ask them to try and form a national unity government.
@highlight
NEW: Politicians in Greece hold unsuccessful talks to form a government
@highlight
NEW: Socialist PASOK leader to meet with Greek president
@highlight
A poll find leftist Syriza party growing in popularity
@highlight
New elections must be called if a new government isn't formed by Thursday
"Venizelos and Samaras are sticking to the points that they signed in the bailout," Tsipras said after meeting with @placeholder.