Members of the U.S.-based Free Gaza Movement said they would take doctors, aid workers and European parliamentarians to Gaza.
"We cannot wait until Israel decides to stop the killing and then open up Gaza for the international community and aid workers to pick up the pieces," said Huwaida Harraf, one of the organisers.
"We insist on the right to enter, we are not going to let the violence Israel may use against us stop us," she told Reuters.
Israel launched its offensive 17 days ago with the declared aim of ending cross-border rocket attacks from the Hams-ruled territory.
Medical officials said the Palestinian death had risen past 900.
Israel says 13 Israelis have died -- three civilians hit by rockets and 10 soldiers.
The group of 34 have chartered a small Greek-flagged ferry, after another vessel was shot on Dec. 30 by Israeli when it was taking aid to Gaza from Cyprus.
Metal panelling was fitted to the body of the vessel before leaving. Some activists said it was for security reasons.
A representative of the activists said Israel, which patrols the waters off the Gaza strip as an occupier, had been made aware of activists' aim to enter the territory.
British doctor Sonia Robbins, who has worked at hospitals in Gaza, said the situation in the enclave was a humanitarian disaster.
"They have declared war on a virtually defenceless population," she said.
"The defence the Palestinians have are home-made fireworks ... which can kill like any firework fired directly at you. They can only dent a wall and not demolish a 15 storey house and the family in it."
The trip, including parliamentarians from Greece, Spain and Belgium, is expected to take about 25 hours. Free Gaza has sent regular shuttles of aid to Gaza from Cyprus since August.
Last Mod: 12 Ocak 2009, 16:04