Your character Harry Woods is very loveable, how similar are you to him?
Well of course I am loveable! Harry he is really old school. I found a lot of empathy with that character; he is not a hero, he is just a guy who is doing a job.
Do you think if the Nazis had taken over you would have been part of the Resistance like Harry?
I think if they had managed to invade, peoples main concern would be their families’ safety and nothing else. A lot of people would have got on with it and kept their heads down.
What did you discover from being in the series?
We went to a premiere of it in Berlin and it was very interesting. Young Germans still feel a great responsibility for the Second World War. But given the political economic climate, any country could become like that.
What can we expect from tonight’s final episode?
There is a terrific catch you will love it. It’s shocking.
Does Harry survive?
We shall see. It would be very sad if I got killed.
What was it like working with Sam Riley who plays Harry’s boss Douglas Archer?
I loved working with him, we had so much fun.
Is Sam’s voice as husky in real life?
Yes, I think it’s the fags.
What are you most proud of in your career?
The Pyramid Texts, which is a one-man film about an old boxing trainer talking about his life. It’s all about fear and loss. That’s the one film out of my 53 years as an actor that I can actually say I am proud of what I did.
Was it fun going back to do Trainspotting 2?
Yes I was amazed when Danny Boyle phoned me up. I still haven’t seen it, but It was wonderful to go back and work with him and Ewan McGregor.
What do you get recognized for the most?
Game of Thrones, and that stupid programme I was on (Celebrity Big Brother). But I think I will always be remembered for Braveheart.
Why after all your success did you want to do Celebrity Big Brother?
I was very nervous about doing it, but there was a financial consideration, which was substantial. I am very interested in the media and reality TV and what it means to our society. I thought maybe I could behave in a way that is not disgraceful and try and show in those circumstances that you can behave properly.
SS-GB concludes tonight at 9pm on BBC One. The DVD is released on March 27.