Mandela was very much alive and knew what we were doing when we were making the film. He himself has said he doesn't want to be remembered as a saint, he wants to be remembered as a man. Ans he was a man. He was a young man. He had hopes and ambitions and dreams that were just like any other young man who wanted to be the best of what he did, and have a family and children, and to be a great lawyer, and to be a success. And this pernicious evil - drip, drip, drip effect on him - it just did not stop. Everything I researched led back to this man, and what it cost him as a man, a flesh and blood man who was a dad who had hopes and dreams. I want my sons to go and watch that and see. I mean, isn't that what makes this journey all the more extraordinary?

When you talk to people now in their 80s and 90s who knew Mandela as a young man, they remember a brilliant lawyer and a fantastic orator, but they also remember a 'star'. He had a magnetism about him. He gave off electricity when he came into a room. Idris [Elba] can do that too - he has that warmth and radiance about him.