Cate Blanchett admits working with Steven Soderbergh and Michael Fassbender was big reason why she signed up for Black Bag

Cate Blanchett admits that working with Steven Soderbergh and Michael Fassbender was a big reason why she signed up for 'Black Bag'.

The 55-year-old actress features in the upcoming film – in which she and Fassbender play married spies – and says that the collaborators persuaded her to join the cast.

Cate told Empire magazine: "I did a film with Steven called 'The Good German', that basically only my mother saw. But I had a great time. When you hear, 'Spy thriller, Soderbergh, Fassbender', you're like, 'When do I show up?'"

The duo play intelligence agents George and Kathryn Woodhouse, whose relationship is put to the test when Kathryn is suspected of betrayal and George is sent to hunt her down, and Blanchett was impressed by the "interesting" exploration of marriage.

The 'Lord of the Rings' actress explained: "It's a really interesting way of exploring marriage. (George and Kathryn) have this great sexual and intellectual connection, but there's so much they don't know about each other.

"That's how some relationships work: 'There are certain things I can't tell you, because they won't help you. In fact, they'll probably hurt you'.

Fassbender added: "The story was so engaging. This is not the crash-bang-wallop spy film. It's about brains and emotion."

Cate revealed that she and Michael prepared to play a couple by going for lots of dinners with the filmmaker.

The 'Tar' star said: "Steven likes to go out to dinner, so we did that a lot.

"There's actually a really long dinner scene in the movie, so Michael and I spent a lot of time looking into each other's eyes during that."

Cate was intrigued to discover that many female spies have been successful because of the "misogyny" against women in the profession.

She said: "I found it interesting that, historically, female spies have been very successful due to misogyny. No-one expects a woman to do a job like this – which makes them great at it."

Blanchett's early acting roles came on the stage and she recently revealed that she was content with a career in theatre as she "never, ever" expected to breakthrough in the movie industry.

The two-time Academy Award winner said: "I was resigned, happily, to a career in theatre. I didn’t think I was that girl. There was a sense women had a certain ‘shelf life’ in the film industry and a certain type of women got to parade on the screen and others didn’t."