Old Etonians Dominic West and Prince Harry are set to go head to head in a "gruelling" race to the South Pole.
The Hour actor will be up against Prince Harry and a team of wounded British servicemen and women, as well as a team from the United States, in the 208-mile (335km) trek in the Walking With The Wounded South Pole Allied Challenge in November and December this year.
The Commonwealth team - of which Dominic will be a member - will be made up of wounded servicemen and women from Canada and Australia.
Confirming his intention to join the trek, Dominic said: "I agreed to do a walk to the South Pole with these wounded soldiers in December, so I'm trying to train for that at the moment."
A spokesman for Walking with the Wounded said The Wire star has already completed "secret training" on glaciers in Iceland.
The spokesman said: "He will be joining the Commonwealth team as a celebrity team mentor.
"He will be taking part in the full trek to the Pole, enduring gruelling conditions of up to minus 50 degrees.
"In fact, he has spent a week in Iceland for secret training on glaciers with his team and only got back on Thursday night. "
Harry, who took part in the charity's trek to the North Pole in 2011, is already patron of the Antarctica expedition, and confirmed in April he will be taking part with Team UK - also known as Team Glenfiddich - for the whole race.
He missed out on a bid to conquer Mount Everest with the group last year because of his military commitments and he withdrew early from the successful North Pole expedition to attend his brother's wedding.