The film has come under criticism for its violent confrontation between Batman and The Joker and the story's bleak tone.
Keith Vaz MP of the Home Affairs Select Committee told The Independent: "The BBFC should realise there are scenes of gratuitous violence in The Dark Knight, to which I certainly would not take my 11-year-old daughter. It should be a 15 certificate."
However, the film censor has defended its ratings system, stating that the superhero sequel fell within the rules of a 12A certificate by implying violence as opposed to showing it in explicit detail.
BBFC spokeswoman Sue Clark said the certification was partly down to the fact that the movie was based on a comic book.
"Batman can jump off buildings and fly and The Joker is not a realistic character and bounces back with a smile on his face," she said.
Clark added that giving the film a 15 rating would prevent the majority of the Batman fan base from watching it.
"Younger teenagers would not have been able to see it, and they are the very people who are going to love it," she explained. "We would have ended up with far more complaints from people who wanted to see the film and couldn't."
> Click here for our review of The Dark Knight