The prime minister must accept Shipping Minister Panagiotis Kouroumblis' resignation, New Democracy (ND) leader Kyriakos Mitsotakis sid on Thursday while touring areas affected by the oil spill in the Saronic Gulf.

"There are grave responsibilities and major questions," said the main opposition leader and asked: "Who said that the tanker was seaworthy and why was the state mechanism's response delayed? How can a ship sink in completely calm seas?"