A Michigan teen's lonely battle is now a star-studded cause célèbre -- Ellen DeGeneres, Demi Lovato and some members of Congress have all joined her fight to lower the R rating of the documentary film Bully down to PG-13.

High school student Katy Butler, a victim of bullying, launched a petition at Change.org, lobbying the Motion Picture Association of America to change the rating so a more youthful audience could see the film. 

"It's an important movie for everyone to see, especially kids," DeGeneres said on her talk show recently, with Butler present.

DeGeneres and Lovato both urged their Twitter followers to sign the petition. Lovato wrote: "Please help repeal the R rating on 'BULLY.' EVERYONE should be able to see it." 

New Orleans Saints quarterback Drew Brees and actor Avan Tudor Jogia are also on board. 

Butler's petition, delivered to the MPAA's Los Angeles office last week, has the support of at least 26 members of Congress and is picking up steam. 

"We've got the MPAA's attention, and with nearly 300,000 signatures and support from celebrities and politicians, there's now a national movement of people calling on the MPAA to drop the R rating for Bully," Butler says. "As someone who lived through bullying day in and day out in school, including having my finger broken by bullies, this film is too important to silence with an R rating. Everyone should have a chance to see Bully."

Studio exec Harvey Weinstein, whose company is releasing the film, has appealed the MPAA rating, to no avail.  

A special screening of the documentary, which was given an R rating based on profanity, will be held for educators in Washington, D.C. on Thursday, followed by a panel discussion about peer pressure and bullying. 

The documentary is set for release on March 30.

Watch the trailer here:

Tags: Movies