Evangelos Venizelos, a former Greek Socialist party leader and deputy prime minister, has quit the party, accusing its leader of aiming to turn the party into an adjunct of ruling left-wing Syriza party.

Venizelos announced he is "free of party ties" moments after meeting with party leader Fofi Gennimata, who told him she would appoint former Athens mayor George Kaminis, not him, at the top of the list of candidates for the 12 at-large seats in the Greek Parliament for the July 7 national election.

Venizelos said Gennimata told him she was considering appointing him to the 12th "honorary" position on the list.

Venizelos, 62, has served as Greece's finance minister, from 2011-12, and its foreign minister, 2013-15, as well as deputy prime minister. He was Socialist party leader from 2012 to 2015.