Margot Robbie felt ''terrified'' playing Queen Elizabeth I in 'Mary Queen of Scots'.

The 28-year-old actress stars alongside Saoirse Ronan - who plays the titular role - in the Josie Rourke-directed drama, and Margot has admitted to initially being intimidated by the prospect of playing the British royal, revealing she actually rejected the opportunity when it was first offered to her.

Margot shared: ''I automatically said no ... I was terrified at the prospect but the script was brilliant - Beau Willimon crafted it in a very pacey, political way. You know, he wrote for 'House of Cards' and he's brilliant.

''Josie, our director, this was her first feature film but she's a very accomplished director in the theatre world and in her own right. And I loved talking to her.''

Margot also admitted she was eager to work with Saoirse.

She told CNN: ''I knew Saoirse already through personal avenues and have always adored her work and wanted to work with her ... so there was everything there that would make me be like, 'Yes, I want to do this project.'

''But, the role itself terrified me and initially I said no.''

Meanwhile, Margot recently admitted she felt ''embarrassed shooting her most raunchy scene in 'The Wolf of Wall Street'.

The actress rose to worldwide prominence through her starring role in the Martin Scorsese-directed drama, but she confessed to feeling ''very weird'' during the scene in which she had to seduce her on-screen husband, played by Leonardo DiCaprio.

Margot said: ''It doesn't come across when you're watching the movie, but in reality we're in a tiny bedroom with 30 crew crammed in. All men.

''For 17 hours I'm pretending to be touching myself. It's just a very weird thing and you have to bury the embarrassment and the absurdity, really deep, and fully commit.''