A POTENTIALLY deadly cargo of weapons-grade plutonium - enough to make 40 nuclear bombs - is to pass along the Dorset coast on its way to France.

Two armed British ships are said to be carrying the world's first seaborne cargo of the material, from US atomic missile warheads.

Fears have been raised that the Pacific Pintail and Pacific Teal, carrying 140kg of bomb-making plutonium, could put millions of lives at risk if disaster strikes.

Amid heightened fears of Al-Qaeda terrorist attacks, the voyage has been condemned by local Greenpeace activists, who intend to protest when the ships dock in Cherbourg on October 4.

The British merchant ships, equipped with 30mm cannon and 13 armed British commandos standing guard on the decks, are thought likely to enter UK waters on Thursday and sail within 12-20 miles of the Lizard peninsula before passing along the coast in the shipping lane.

The congested Channel is the world's busiest waterway and environmentalists believe this is the most likely part of the 2,000 mile voyage for potential disaster.

"We are deeply concerned about the trafficking of bomb material. There is no reason for this transport," said Shaun Burine of Greenpeace, speaking from Cherbourg.

He said it was a commercial decision to ship the material to France for reprocessing and next year the trip would be done in reverse.

"In the event of a ship fire or terrorist attack you are looking at the dispersal of very small plutonium particles in the atmosphere, which can easily be inhaled," he said.

Jim Knight, MP for South Dorset, pointed out that nuclear research had been carried out at Winfrith and nuclear submarines visited Weymouth harbour without any problems.

"The principal concern I would have would be the security and it sounds as if that has been addressed," he said. He said all the authorities along the South Coast were required to have disaster planning in place.

Borough of Poole environment portfolio holder Cllr Don Collier said: "I'm concerned that the movement of this material is done in a proper manner and at least risk to anybody."

Poole MP Robert Syms said: "I'm not concerned unless anybody has any information it's being carried in an unsafe manner, then I would take it up in Parliament."

First published: September 28