Explorer to tackle 'greatest journey'

Mr Dickinson, 49, who will take two months to complete his journey, will be sponsored by the Darlington-based light commercial vehicle hire, Northgate plc.

As there is no land at the North Pole, Mr Dickinson and his partner, Richard Webber, will travel over thin, constantly shifting sea ice, interspersed by open stretches of water called leads.

Experts have confirmed that the effect of global warming is thinning the ice and that, in less than 20 years' time, such an expedition will be impossible as the polar cap will be so thin.

The shrinking ice is diminishing the polar bear's territory and the fear of being attacked by these majestic yet ferocious creatures will be a constant threat.

Added to these pressures is the necessity for the two men to carry all food, fuel and equipment in their pulks (sledges), each weighing as much as the average rugby player - 330lb or 150kilos.

The trek will be unsupported, so no dogs or kites will be used, and there will be no re-supplies. Typical temperatures will be -25C but could get as low as -60C.

Last winter, Mr Dickinson, of Hexham and his wife, Hilary, trekked from Hercules Inlet, in Antarctica, to the geographic South Pole, becoming the first British married couple to do so.

Mr Dickinson said: "There really is only one great journey left for me and it is this one.

"As I reckon I'll only have one chance to achieve it, I want to try it unsupported from the Canadian side, considered the toughest expedition in the world. It's my national and northern pride that will be driving me along.

"It's a great boost to know, too, that I have the support of Northgate, whose ethos is similar to mine."

Alan Noble, executive director of Northgate, said: "As the company celebrates its 25th anniversary this year, it is appropriate that we become involved in supporting Conrad, who is already establishing himself as a very modest polar legend.