"We are going to stay here for as long as we can. We are determined to stop this headlong rush into a war with Iraq that will only make the world a more dangerous place," she added.

She said the group had inflatable motorboats in the water around the freighter, watched by waterborne police who had so far kept their distance.

Dart 8 is loading equipment including helicopters, tanks and jeeps at Marchwood, the military section of Southampton port, to supply British troops who will join the thousands of U.S. soldiers already in the Gulf region.

The protest is Greenpeace's second action in the port in a week.

The Ministry of Defence failed last week to get an injunction stopping Greenpeace from blocking the port but did obtain a limited ruling preventing the activists from boarding or touching ships chartered to carry military supplies.

A ministry spokesman said Saturday's blockade was making it difficult but not impossible to load the ship. "They are creating difficulties but we have a range of contingency plans," he told Reuters. He declined to say when the Dart 8 was due to sail.

Prime Minister Tony Blair met U.S. President George W. Bush at the White House last week for what many saw as a council of war. Both insist Iraq is hiding weapons of mass destruction from U.N. weapons inspectors and must disarm voluntarily or be disarmed by force. Iraq insists it has no such weapons.

Bush said time was running out for a peaceful end to the crisis, while Blair said on his way home that he believed the U.N. Security Council would pass a second resolution condemning Iraq if it continued to stall the inspectors.

U.S. Secretary of State Colin Powell is due to present to the Security Council on Wednesday what he says is compelling evidence that Iraq is concealing weapons programmes from the U.N. inspectors.