The Girl On The Train stars Emily Blunt and Luke Evans have revealed their embarrassment at not having read the best-selling book that the film was adapted from, when they signed up to their roles.

Emily and Luke take two of the lead parts in the thriller by Paula Hawkins, but neither had joined the throngs of readers who could not put down the novel when it was published in 2015.

Emily and Luke star in The Girl On The Train (Ian West/PA)

Being interviewed about the project on The Jonathan Ross Show, Emily admitted: “I think because I saw everyone reading it, I was trying to be contrary and say, ‘Well I’m not going to read it if everyone’s reading it’.

“I was pushing back against the train and then I got offered the film and then shallowly ran to the bookstore to get a copy.”

Luke said he had been caught out trying to cover his tracks in reading up on the part after having been announced as one of the stars.

Paula Hawkins, Emily Blunt, Rebecca Ferguson and Haley Bennett at the film’s premiere (Ian West/PA)

He said: “I read the script and then quietly one evening I went to a late bookstore and asked ‘Can I get Girl On The Train?’ with my hood up and (the shop assistant) said, ‘I hope you don’t mind me asking but shouldn’t you have read it before you got offered it today?’.

“I said, ‘Please don’t tell anybody I haven’t read it!’.”

The film, which is released on October 5, shot while Emily was hiding her pregnancy, but she had to tell her news to co-star Luke ahead of a particularly physical scene.

Emily Blunt (Ian West/PA)

He said: “Emily told me just before I had to throw her around her kitchen. It was going to be a stressful and intense day anyway, so we gave each other a little hug before we did the first take and as she leaned in she whispered, ‘I’m four and a half months pregnant’.

“No one really knew at that point and so we kept it quiet and managed to get through that day.”

The Jonathan Ross Show airs on ITV on Saturday at 10.20pm.