Homeland actor Damian Lewis has revealed that his co-star Claire Danes passed the time on the set of the show by taking part in smartphone game Words With Friends.

The Romeo And Juliet actress stars as bipolar CIA agent Carrie Mathison in the US drama, which begins on Channel 4 on Sunday – while Damian plays a former war hero who may not be all he seems.

He described his co-star as “whip-smart, extremely committed and focused”, and added, “She plays that interactive Scrabble game, Words With Friends, endlessly.

“She has about five or six games going on with different people, and got half the crew doing it as well. It’s her way of relaxing.”

Damian added that viewers could expect to see an interesting dynamic between the two characters.

“Ambiguity is a complex thing to play. You have to be lightning quick and nimble, there’s a mental and imaginative agility in the performance which is really fun,” he said.

“Inserting a bipolar disorder into the heart of a paranoid thriller is a brave move, as it conveniently allows us to judge Carrie. Is this man a danger to the United States or is she over-reacting? It’s intense. You’re going to love it!”