The team underwent Royal Marine training in Norway

Graham Sheperdly, from west London, Paul Jaffe, from north London, and John McCarthy, from Bucks, are taking part to raise money for charity.

They are among seven UK teams competing in the Polar Challenge from 6 April.

The trio also hope to raise thousands of pounds for the Paul Strickland Scanner Centre at Mount Vernon Hospital in north London.

Mr Sheperdly, a roofer from Ruislip, Mr Jaffe, a safety engineer from Wembley, and electrician Mr McCarthy, from Latimer, all work at the Leavesden film studios near Watford.

'Towing tyres'

They are keen on outdoor challenges and last year took part in a Husky 'safari' in Finland.

The men have to put on a stone in weight before the race so they can cope with burning off 7,000 calories on each day of the challenge.

And because it is a race, the men will have to think about tactics while they are trekking in freezing temperatures.

They will calculate their effort and challenges in terms of distance travelled, rather than days, as the sun will never completely set during the two weeks.

Mr Sheperdly told BBC News Online: "We've been doing 24-mile walks each weekend, we've been towing tyres at work during our dinner breaks and this week we've had to constantly eat, and remember to eat, while working as well."

The men have undertaken Royal Marine training in Norway in preparation for the race.