Emily Blunt is a “big believer” in unions “getting what they want”.

The ‘Oppenheimer’ actress, 40, finished her promotional duties for Christopher Nolan’s drama about the father of the atomic bomb just as the SAG-AFTRA walk out kicked off, which has brought Hollywood to a standstill.

She told The Guardian: “I am a big believer in unions getting exactly what they want.

“I’m a huge believer in getting our crews back to work – the people who will suffer most.”

The strike comes after Emily, who has daughters Hazel, nine, and Violet, seven, with husband and fellow actor John Krasinski, 43, recently caused a stir when she said she was taking a break from her career to be with her family.

She also told The Guardian her role as Kitty Oppenheimer – wife of atomic bomb creator J Robert Oppenheimer – could not be further from her nature.

Emily added: “There was something flighty and wild and nonconformist about her.

“It was a time where contortions were happening to women, as they tried to mould themselves into perfect housewives. But Kitty was a terrible mother and she wasn't a very good housewife – and had no desire to be one.

According to Oppenheimer’s biography, Kitty “had absolutely no intuitive understanding of children”.

The film features a string of scenes of her being cold to her kids, and Emily said one of the most stressful to shoot was when Kitty and Robert are driving home with their two-year-old.

The young actor was distraught and crying during the scene and Emily comforted the youngster by singing him to sleep as the camera was reloaded.

They did four further takes, with the child asleep in her arms – but Emily said director Christopher, 52, used the first version “where I looked like the worst mother in the world”.