Keira Knightley had to channel Homer Simpson in her new TV series

She told heat magazine: "We started shooting without having the last two episodes, which was a new experience.

"This was also one of the best casts I've ever worked with.

"There wasn't one person I didn't think was totally excellent or up for the challenge.

"Everyone really got off on the silliness of it, the heightened reality.

"I was asking Joe (Barton, writer) about a particular scene and he referenced a scene from 'The Simpsons'.

"I was like, 'Am I Homer Simpson in this scenario?' I've never been given that reference for a character before!"

The 'Pirates of the Caribbean' actress couldn't resist saying yes to the project when she was told about the "excellent" and complex character she was wanted for.

She said: "I read it and the whole concept made me laugh so much.

"[Joe's] dialogue is so brilliant and he creates such a mad world...

"The idea of the quintessential Tory politician's wife who would have to be so proper, but was actually an undercover agent and spy who went no a deranged killing spree with her best friend, who was an assassin? The juxtaposition of those things was excellent."