Robert Carlyle has said he thought his new drama Cobra was about a snake when he got the script.
The Trainspotting star, 58, plays prime minister Robert Sutherland in Sky's political drama.
But he said at first he thought the title referred to a snake rather than the name of a meeting room - Cabinet Office Briefing Room A.
"I thought it was a script about a snake," said the star. "I didn't know that much at all.
"I spoke to a couple of Scots politicians who told me about it. It's convened quite a lot, these things happen the public don't know.
"So that was new for me."
Carlyle insisted that when he tells people he is in a show called Cobra, "they look at me as if 'Why are you doing a show about a snake?'"
The actor also revealed that making the six-part drama made him sympathise with what prime ministers go through.
Asked if he had sympathy with what they have to do, he said: "Prior to doing this I had absolutely zero I would think.
"But during that time I remember Theresa May was going back and forward to Brussels and she was ageing five years by the week while I was making this and I felt for her.
"Of course she's got a life, she's got problems, the stuff we all have going on in her lives. I felt for her as a human being and from one human being to another."
Cobra - which also stars Victoria Hamilton, Richard Dormer and David Haig - is on Sky One on January 17.