As millions pray for Nelson Mandela, hospitalised for a week with a recurring lung infection, the race is under way to provide the definitive film version of his extraordinary life and times.Leading the charge is a big-budget adaptation of Mandela’s bestselling autobiography Long Walk to Freedom, starring Idris Elba, best known for The Wire and Luther, and Naomie Harris, recently seen in Skyfall.Later this year it could go head-to-head at the box office with Winnie, featuring Jennifer Hudson as Mandela’s wife, the struggle heroine Winnie Madikizela-Mandela, with Terrence Howard as South Africa’s first black president.The casting of foreigners has been controversial in South Africa and accents will be under close scrutiny in the latest films, which represent a transatlantic duel between Britons Elba and Harris and Americans Hudson and Howard.The films will cover much of the same historical territory from different perspectives, but so far it appears something of a David versus Goliath contest. Mandela: Long Walk to Freedom is the most expensive South African movie ever made, whereas Winnie is being released two years late after numerous setbacks.Both come at a time that – with Mandela spending his seventh day in a serious but stable condition in a Pretoria hospital – South Africa and the world are coming to terms with his mortality and taking stock of his life and achievements.Mandela: Long Walk to Freedom, directed by Britain’s Justin Chadwick (The Other Boleyn Girl), is in post-production and due for release in South Africa on November 29. The film spans 1924 to 1994, with two other actors playing Mandela at ages eight and 16. His prison on Robben Island was reconstructed in minute detail at a studio in Cape Town, right down to the keys and locks used on cell doors. Producer Videovision has offered to donate the sets to the Mandela museum in Qunu and other heritage sites.The picture was made in consultation with the Mandela family and his foundation. Producer Anant Singh, who has been working on the project for 17 years, said: "I was thrilled that when Madiba [Mandela’s clan name] looked at some of images of Idris Elba in the trademark Madiba shirt, he asked the question, ‘Is that me?’. This recognition and affirmation from Madiba is extremely satisfying and makes our journey worthwhile.”Secrecy around the project is tight and all requests for interviews were declined. One South African cast member did agree to talk to the Guardian on condition of anonymity. "The sets are incredible,” he said. "When the guys playing prisoners stripped down and the wind blew through, I’m sure it was not dissimilar to what it was like on the island. It was very creepy and eerie.”Elba and Harris were joined by more than 100 South African actors, for whom this was a deeply personal project. "The casting of Idris Elba was a piece of genius,” the cast member said. "He doesn’t look like Mandela at all but they didn’t want a Mandela lookalike.”A British prosthetics team worked on Elba so he could portray Mandela over a period of 30 to 40 years, the actor added. "I like what Idris did with it. I was moved by him. He was very focused and I admired his concentration. Hats off to him.”