People for the Ethical Treatment of Animals hope to place an anti-Jennifer Lopez advertisement in celebrity magazine Heat condemning the singer for wearing fur.
Peta has been targeting J.Lo because, as well as being photographed on a number of occasions wearing fur, she also uses fur in her Sweetface clothing range. It has even set up a website, www.jlodown.com, that calls on people to write to the singer expressing their opposition to her use of fur.
The charity recently paid $5,000 for a full-page ad in American magazine Billboard, but it was pulled at the last minute.
A Peta spokesman said: "We have deliberately singled out J.Lo because she has made herself the face of fur fashion and is a very high-profile person."