The Northwest Passage is one of the most fabled, and treacherous, sea routes in the world. Many sailors have perished in its freezing Arctic waters after their ships became encased in ice.

Now, as climate change takes hold, British explorers are trying to become the first to sail through the Northwest Passage from east to west, relying solely on wind and oars.

The expedition will demonstrate the advance of climate change, which scientists say is thawing out the Northwest Passage for longer periods each summer.

This has raised the possibility that the route could become an important shipping channel, in a move that would revolutionise trade by offering a short cut between western Europe and the Far East.