Emily Blunt says "mummy cults" put unnecessary pressure on women.

The story - based on the novel of the same name by author Paula Hawkins - tackles aspects of motherhood and Blunt has now opened up the "societal pressure" women face on whether or not they become mothers and the choices they do make if they do become parents.

Speaking at the movie's world premiere in London on Tuesday night (20.09.16), she said: "There is a huge societal pressure on women when it comes to motherhood, and these 'mummy cults' that go on. It makes women feel that they have to be a bit defensive about the choices they make - whether they want to be a mother or whether they don't, whether they want to breastfeed or whether they don't. I could go on and on.

"In the domestic world, I think it's when women can be a bit cruel about each other, more so than any other environment. And I think this film really captures that ... I think women will really relate to the film and see aspects of themselves, or themselves fully, in any one of these characters."

Blunt - who has two children of her own, two-year-old Hazel and three-month-old Violet, with her husband John Krasinski - also admitted she was ready for "some resistance" toward her portrayal of the character from fans of the book but she insists they will have to make do with her portrayal of Rachel "whether they like it or not".

The British beauty - who was pregnant with her second daughter during filming - said: "I think any time a character or certainly a book is beloved, you're going to be met with some resistance to whoever is cast or whoever is doing it. But at the same time, all I could think of is that it's going to have to be my version of her whether people like it or not. Once we started filming it didn't enter my mind that much."

Blunt was joined at the premiere by her co-stars Luke Evans, Rebecca Ferguson and Haley Bennett and director Tate Taylor.