Pop star Miley Cyrus is so keen to play country music legend Dolly Parton in a movie about her life that she is doing everything she can to convince the "Jolene" singer.

But Parton refuses to play favourites, even though Cyrus has been bombarding her with audition tapes.

Cyrus is concerned the role will go to Scarlett Johansson, reports contactmusic.com.

"Miley is bugging Dolly for the role," said a source.

"This movie is her legacy, and she told Miley she doesn't have the acting chops to pull it off.

"Dolly is holding out, though, and isn't 100 percent on Scarlett either. She'd consider Kristin Chenoweth or even Jessica Simpson," added the source.