Latest News reports say airlines are supporting the blockade by refusing to take passengers.
The Spanish Iberia airline said it had been asked by the Israeli government to increase security checks on passengers bound for Tel Aviv. As of next week, Iberia will be advising passengers with that destination to check in one and a half hours prior to boarding time.
Gaza TV News reports that Air France are the latest airline to bow to Israel's wishes by cancelling flights for those intending to fly to Israel this Sunday
Mick Napier, a British activist coordinator, said the group would sue any airline which refuses to board activists bound for Israel.
He said organizers have not compiled a complete list of all the Europeans and North Americans who have booked flights for the "Welcome to Palestine" campaign, to prevent Israel from discovering the list and blocking their entry.
"We're not being conspiratorial here, but we don't want to make the Israelis' job easy," Napier said.