With the success of “The Iron Lady,” a film about the first woman Prime Minister Margaret Thatcher, British producer Stephen Evans will soon begin casting for a £30 million biopic about the ill-fated Princess Diana of Wales.

But the big question is who will play the royal beauty?

According to rumors, Charlize Theron and Carey Mulligan are battling it out for the role.

Apparently, Charlize is a strong contender, but she is 36 (63 in Hollywood) and the film is depicting Diana before her divorce from Prince Charles.

This could definitely work in Carey’s favor who is only 26.

The film will be based of Diana’s former bodyguard’s memoirs, “Diana: Closely Guarded Secret,” which he released in 2009.

Ewan McGregor will most likely be playing the role of Ken Wharfe, the bodyguard.

“The emphasis on this really is authenticity and to discover what she went through. Unless you are a Diana freak, quite a lot of it will be unknown to the audience,” says Evans.

So who’s your choice to play Diana, Charlize Theron or Carey Mulligan?

Tell us what you think in the comment section below…