(Cover) - EN Movies - Hayley Atwell accepts that she is not as "great" as Dame Helen Mirren.

The British actress, who is starring in upcoming blockbuster Captain America: The First Avenger, admitted there was a time when she feared people might think she was too "worthy" and serious.

The gorgeous brunette, who has appeared in a number of period dramas including The Duchess, said that after years of playing serious roles, she is looking forward to getting stuck into a superhero film.

"I'd done a lot of theatre and adaptations and I thought, Am I getting a reputation for taking myself too seriously? I'm not as good as the greats; I'm not Helen Mirren, maybe I should be more commercial.'" she told Total Film. "It felt like an exciting challenge, to do something that wasn't too worthy'."

The 29-year-old star is taking her role very seriously. Although she enjoyed getting involved in a less solemn project, she was very aware of not portraying her character Peggy Carter, Captain America's love interest, as too light-hearted and one-dimensional.

"I think Joe [Johnston, the director] cast me because he wanted someone to bring a truth to her," she said. "I wouldn't be sending her up all the time. I'd try to explore her as a woman struggling to make her mark." (C) Cover Media