Do these people have any proof whatsoever to such claims? asked Israeli foreign ministry spokesman Yigal Palmor. Their entire activity is aimed at demonizing the state of Israel. What are they saying, that we have used all the Jewish bankers in the world to cancel Greece's bonds? What kind of fantasy world are they living in?

Organizers of one boat planning to join the flotilla, the U.S.-registered Audacity of Hope, released a statement Sunday asking the Greek government to explain why the leased vessel was being prevented from leaving a Greek port.

Passengers and crew say they are being told the boat cannot depart because of concerns about its seaworthiness and the need for further inspection.

Trip participants rejected the explanation, claiming the boat was safe. They suggested economic pressure was being brought to bear on Greece.

Israel has said openly that it is pressuring governments to try to stop the flotilla, and clearly Greece is a key government since several of the boats plan to leave from Greece passenger Medea Benjamin said in a news release by the boat's organizers. It is unconscionable that Israel would take advantage of the economic hardship the Greek people are experiencing to try to stop our boat or the flotilla.

In the news release, the boat organizers -- U.S. Boat to Gaza -- suggested without offering proof that political leverage was being used with the International Monetary Fund in a bid to compel Greece to block flotilla ships from departing.