TV
The 27-year-old actress, who plays Belle de Jour in the ITV drama, also suggested that the upcoming fourth series will be the programme's last.
"I'm about to start filming the fourth series and then that will be it," she told The Sun. "I'm not sure it has legs past four seasons so we're trying to develop a movie."
A source added: "The book has been a worldwide success and the TV show has been a hit on both sides of the Atlantic. A movie is the next obvious step.
"Billie's career would skyrocket if the movie took off. It's the springboard she needs to take her talent to the States."
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