Keira Knightley is struggling to cope on the set of her latest film, Silk.

The actress is feeling "drained" due to demands made by Canadian director Francois Girard. He has insisted that she and co-star Michael Pitt, who plays her French husband, speak with the same accent.

"The director has settled for a continental accent," an insider told the Sunday Mirror. "Despite working with a voice coach in London, Keira has found it tough. They've only just started filming, but she's already feeling really low and drained."