The trekkers, who trained by pulling tyres, will drag a 70 kg sled

The trek, considered one of the world's toughest races, starts from Resolute Bay, in Canada, at 1800 BST on Wednesday.

The 11 novice competitors, split into four teams, will cross some of the most desolate terrain on the planet as they race for the magnetic North Pole.

Among them are ex-jockey Richard Dunwoody and former Pans People dancer Babs Powell, the only woman taking part.

One man pulled out

The teams also include Steven East, a broker from Surrey, and company director Christian McLeod from Chichester, West Sussex.

Four men have entered from London - physician Mike Krimholtz, professional sailor and entrepreneur Manley Hopkinson, Croydon police officer Casper Hays and Richard Raine.

Gloucestershire has sent three competitors - writer Phil Ashby, company director Mark Harris and Tony Martin, an events manager from Cirencester.

A 12th entrant, Norman Butler from Swindon, was forced to pull out at the last minute because he had not raised enough money.

Sub-zero gym

The teams will each pull a 70-kilogram (154 lb) sled of supplies and equipment, as they walk and ski across the ice.

The journey is expected to take 30 to 40 days - with the Wedgewood Blue Ice Trophy waiting for the winning team.

The competitors' pre-race training included dragging tyres and even a plane around an airfield, and setting up a sub-zero gym in a supermarket freezer.

Proceeds from the race, organised by explorer David Hempleman-Adams, from Wiltshire, will go to the Bobby Moore Foundation.