Lily James was "overwhelmed" when she danced with Meryl Streep

She said: "Everywhere you look there were these movie legends, and it was very overwhelming. Not to mention the fact that I danced with Meryl, which that’s something that only happens in your wildest dreams. We were all wearing these ridiculous costumes, and there was fireworks, and there was smoke, and there was glitter. It was so mad."

And the 29-year-old actress found it "very daunting" taking on the role.

She added to Vulture magazine: "Obviously it was very daunting, and part of me thought, Oh God, I don’t know if I can do this. But then I watched 'Mamma Mia!' and reminded myself I’m playing young Donna Sheridan, not a young Meryl Streep. Meryl Streep, who’s one of the greatest actresses of all time, had created Donna Sheridan, and so therefore I had this whole world of inspiration, and character to draw on, and to try and bottle and capture and study that essence of what made Donna this fearless, ballsy, brilliant woman - try to pick a few characteristics, or expressions, or a physicality that would make the watcher hopefully believe that my version of Donna would grow into hers ... Getting into the overalls was probably the moment where I was like, Oh, my God. Meryl does this funny little leg pop [in the overalls], and she does this mad little dance. I watched it over and over and over."