Joy Smith, a Conservative who represents a Winnipeg-area riding, says she hasn't seen the film herself.
But Smith says the depictions of bondage and sado-maschism in it encourage people to view violence against women as normal.
E.L. James, who wrote the popular "Fifty Shades of Grey" book trilogy, has said that whatever goes on in the books and the movie is safe and consensual.
Smith counters that she's worked for years with abuse victims, and that they often agree to degrading activities out of fear, or because they believe it's expected of them.
Smith says it's wrong that the movie was launched for Valentine's Day.
"This is not love. It is not a love story. It's a story of the abuse of women," Smith said Saturday in Winnipeg.
"When this happens to women, they hurt when they get whipped. They hurt when there's violence against them."
The movie, which opened Friday, is about a college student and her torrid affair with a 27-year-old billionaire with a penchant for bondage, discipline, sadism and masochism.
Smith compared it to the 1990 movie "Pretty Woman," which depicted a prostitute who meets a handsome and wealthy prince charming. She said in real life, it doesn't happen that way.
Smith said she's received hundreds of supportive emails since calling for the boycott. Most, she said, are from women sharing their own stories.
She said she doubted most of the women who bought the "Fifty Shades of Grey" book, or are going to the theatres, know what it's actually about before paying their admission.
In B.C., owners of the Raven's Cry Theatre in Sechelt said they wouldn't show the film over the movie's 18A rating.
Smith said she was unaware of an endorsement Laureen Harper made of a "Fifty Shades of Grey" cat adoption campaign in Ontario.
The prime minister's wife tweeted she is encouraging people to adopt grey cats at the Windsor Essex County Humane Society, which lowered its fees to 50-dollars on Saturday in a promotion called ''Fifty Shades of Grey ... Cats.''
Harper's message included a poster picture of a grey cat, with a caption below it that read: "Due to the nature of this program, adult cats only."
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