Benedict Cumberbatch believes a successful marriage requires constant work

The actor - who has been married to Sophie Hunter since 2015 - told the BBC: "Don't be complacent and keep the conversation between you going rather than thinking one of you is always right.

"It's also important to be tolerant, understanding and never stop working at it."

Benedict also revealed that he relished the experience of working with Olivia on the movie, observing that they have complementary acting styles.

The actor explained that they "get on incredibly well" and that Olivia knows hope to cope with his "faffing".

Speaking about their professional partnership, he said: "I fret, she doesn't faff, she's really patient with my fretting and I love her non-faffing. We really do get on incredibly well."

Benedict added that the "whole project was based selfishly on us wanting to work together".

Meanwhile, Benedict recently revealed that he refuses to be away from his family for more than two weeks at a time.

The actor explained that he has a "two-week rule" with his family, because he wants to retain a close bond with his loved ones.

Asked what irritates his family, Benedict said on the Happy Sad Confused podcast: "Being away from home p***** them off."

Benedict - who has Christopher, ten, Hal, eight, and Finn, six, with Sophie - also hates being away from his family for long periods of time.

The movie star explained that he tries to prioritise his family life by implementing the "two-week rule".

He said: "It p***** me off too, so we try and do as much to make that not the case - the two-week rule, and try to work as hard as possible on making work happen here nearer home so I can get home, or take them with me."