David Coulthard is backing his old rival Michael Schumacher in the "greatest challenge of his life" as the star fights for his survival after a skiing accident.

Former Formula One driver Coulthard, now a BBC commentator, said: "This is a freak accident. It's not the first one we have seen this winter in the Alps. All the cards are stacked in his favour." It came as messages of support flooded in for Schumacher, who suffered a brain injury after hitting a rock.