Dame Helen Mirren thinks Russell Brand is "intimidating".

Although the actress is now good friends with her 'Arthur' co-star she admits she was full of "terrible trepidation" about shooting the film because she had worked with him before and had not gotten to know him properly.

In an interview with Stylist magazine, she said: "I kind of jumped, but with terrible trepidation. Mostly because it was Russell! We had worked on 'The Tempest' together but never really spent time together until this. Russell is quite an intimidating person."

The 65-year-old star was so nervous of the funnyman's big personality she even worried that she would appear "boring" and dated next to him - but when she met him again found she "fell in love" with him.

She explained: "He's so brilliant and rock and roll and I feel so boring and ordinary next to him. So it was quite scary. And I'm not very good at edgy, modern comedy. But in the film meeting I saw this incredibly bright and interesting person making this thing happen - and I fell in love."

Earlier this year, the Oscar-winning actress admitted she was also "terrified" of Russell's bad boy reputation, not realising he was just as scared of her when they first met because of her impressive career.

He said: "I was frightened before I met her, it made me talk a bit different - like my breathing changed."