Fifty Shades of Grey still
A still from the film adaptation of Fifty Shades of Grey, to be released on Valentine's DayUniversal studios

Several religious groups have condemned the erotic, bestselling book-turned-movie, Fifty Shades of Grey, saying it degrades women and endorses sexual violence.

Buffalo Bishop Richard Malone has written a letter to members of the U.S. Conference of Catholic Bishops saying: "The contrast between the message of 'Fifty Shades of Grey' and God's design for self-giving and self-sacrificing love, marriage and sexual intimacy could not be greater."

Critics, including the American Family Association and National Centre on Sexual Exploitation, are urging moviegoers to boycott the film.

"This is not a healthy thing to mainstream. We'd like to see theatre chains refuse to take the movie," American Family Association President Tim Wildmon told The Associated Press.

The National Center on Sexual Exploitation has gone to the extent of launching the website, http://www.fiftyshadesisabuse.com, to condemn the movie.

"What's unique about it, is the overall message is that they're trying to glamorize and romanticize violence against women. It's such a lie," said Amanda Smith, spokeswoman for the National Center on Sexual Exploitation.

"Telling women that they should want to endure this kind of physical abuse and telling them that women want it, and also pushing the lie that if women are obedient and subservient enough, then they can fix a violent and controlling man."

The movie is based on the 2011 bestselling erotic romance novel by British author E. L. James about a college student and her affair with a 27-year-old.

Author of the erotic novel, E.L. James, defended the subject matter saying: "Who is interested, as a woman, in reading about abuse? Why have these books taken off if they are about abuse?

"Domestic violence, rape, are unacceptable. They are not entertaining in any way. Let me be absolutely clear. Everything that happens in this book is safe and consensual. .... What do I need to do to convince people?"

Meanwhile, a Facebook page titled 'Fifty dollars not Fifty Shades," urging people to donate the cost of a movie ticket and popcorn to women's shelters, has received over 9,500 likes so far, reported AP News.