Keira Knightley has praised the "wonderful dialogue" in her new movie The Edge of Love.

The biopic about the life and loves of poet Dylan Thomas (played by Matthew Rhys), was penned by Knightley's mother Sharman Macdonald.

It casts Knightley as Dylan's first love Vera Phillips, and Sienna Miller as his wife Caitlin.

The actresses have described making the film as very fun and natural.

Knightley said that often the dialogue in films isn't particularly good - but her mother's script was different.

"I have an enormous amount of respect for her talent, and it was wonderful to actually get to play in a piece of work of hers. It was just a joy."

The movie is set to open the Edinburgh Film Festival on Wednesday.

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