A British-born man and his father are hoping to become the first insulin-dependent diabetics to trek to the South Pole.

Will Cross, 35, who became the first Type 1 diabetic to reach the North Pole last year, set off on the 730-mile expedition from Antarctica in early November.

His official website said he was "delighted" to begin the walk after more than two years of planning.

Describing Antarctica as "fickle, unpredictable and vast", he admitted that pulling sleds laden with heavy equipment in the extreme cold weather was making their journey "very difficult".

Oldest trekker

Will, who is now an American citizen and lives in Pittsburgh, Pennsylvania, will be joined by his father in early January for the last 120 miles of the trek.

If successful, retired RAF group captain Mike Cross, 60, will become the oldest person in the world to reach the South Pole on foot.

The ice and snow were hard with lots of chunks of sharp rocks

Will Cross Antarctic trekker

He has previously completed expeditions across several deserts including the Sahara.

Mike, who is also diabetic and lives in Ruskington, Lincolnshire, said his son would currently be facing the most difficult part of the journey, climbing over the Antarctic mountains pulling a sled weighing 150 pounds.

As well as having to cope with temperatures of -45 C and 10,000 foot mountains, the two diabetics will have to ensure that their insulin does not freeze.

The pair hope to reach the Pole by mid-January, becoming the first father-and-son team to complete the trek.

Will said in a report on his website: "We spent the first two days walking without skis.

"The ice and snow were hard with lots of chunks of sharp rocks. We didn't want to risk ruining our skis, so we pulled without them."

'Shackleton' support

The team was supported and encouraged by the granddaughter of explorer Sir Ernest Shackleton, who died in his attempt to reach the Pole on foot.

Alexandra Shackleton, the patron of the expedition, gave them an original 1915 photograph of her grandfather taken before his fateful journey.

Both Will and Mike hope their trek will inspire young people with diabetes to "follow their dreams" and not to allow the disease to limit their lives.

More than �20,000 has been raised so far and will be donated to two charities, the Juvenile Diabetes Research Foundation International and Diabetes UK.