Polar bears can be forgiven for rubbing their eyes and doing a double take as three Elvis impersonators ski past them at the North Pole.

The barren part of the world may be the place you would least expect to bump into The King', but three pals will be messing up their blue suede shoes in the frozen Arctic wastes to raise money for Great Ormond Street Children's Hospital.

Alex Tate and Jonny Clayton, who met while studying at Oxford University, have joined forces with Steve Goodair to take part in the Sony Challenge race which involves trekking 368 miles to the Pole while pulling a 90kg sleigh containing tents and equipment.

The trio will brave temperatures of -40C in the hope of raising £100,000 for an echo ultrasound machine to treat babies.

Mr Clayton's son Jude Elvis Llewellyn Clayton, who is the godson of Mr Tate, underwent lifesaving treatment at Great Ormond Street when he was born.

Jude, who is now four and has fully recovered, adores Elvis inspiring the friends to do the trek dressed as the singer.

Mr Tate, 33, who works in shipping, is originally from Nettlebed, near Wallingford.

His mother Elizabeth said: "He's always wanted to do something like it. He's always been rather keen on ice and snow.

"They say 80 per cent of the world's polar bears are in this area, so I think he will find it quite exciting. They've been given guns so in case of an emergency they can shoot them, and there is an emergency evacuation helicopter, so they should be fine, but a mother always worries.

"This week they pitched their tents in a blizzard and it was -46C. They have been advised to drink nine litres of water a day, but they have to spend two hours melting the snow to make water.

"It's a real adventure and the challenge of a lifetime. It'll either make him very fit or well, or break him!"

The race starts on Sunday. The fastest anyone has completed the challenge is nine days.