Last week, DC Comics artist Chris Sprouse resigned from illustrating a much-anticipated Superman series because the company hired award-winning writer and traditional marriage proponent Orson Scott Card.

“It took a lot of thought to come to this conclusion,” Sprouse said in a statement. “The media surrounding this story reached the point where it took away from the actual work, and that’s something I wasn’t comfortable with.”

So far, DC Comics hasn’t caved to the pressure to fire Card. “As content creators we steadfastly support freedom of expression,” the company said in a statement. “However the personal views of individuals associated with DC Comics are just that—personal views—and not those of the company itself.”

Card’s Superman story is on hold until DC can find an artist to illustrate it. Even though Card’s views on marriage have nothing to do with his work at DC, more than 15,000 have signed a petition against Card, and The Guardian reported some fans have threatened to boycott the comic book giant. Lawyer Jeff Trexler told Wired that firing Card based on religious opposition to homosexuality would create an explosive legal situation.

Card, a Mormon related to Brigham Young, is an award-winning writer who is best known for his Ender's Game science fiction series. He has been a board member of the National Organization for Marriage since 2009.