Greenpeace activists board a ship carrying Volkswagen vehicles as it sails up the Thames estuary towards the port of SheernessReuters

Environmental activists blocked a cargo ship from unloading 1,200 Volkswagen cars in a protest about air pollution from diesel engines.

Greenpeace protesters used kayaks and boats to reach the 23,000-tonne car carrier in the Thames Estuary yesterday. They climbed up and suspended themselves from the ship’s 27m-high unloading door and have said they will remain until Volkswagen “takes its toxic cars back to Germany”. The ship turned around and sailed to Margate with the climbers still in position, according to Greenpeace. Last night three activists were arrested.

More than 40 environmentalists also scaled fences at Sheerness port, Kent, the intended destination of the ship where thousands more VW cars are awaiting distribution, Greenpeace said.

A VW spokeswoman said: “The ship contains a variety of Volkswagen…