A Cologne politician has filed a lawsuit against a local Christian bookstore over a window display that compares abortion with the Holocaust.

Specifically, the shop window of the Marienbuchhandlung book store features a photo of a cemetery in Wiesbaden under the title, “kindermord.org,” or “child-killer.org,” followed by “Abtreiben macht frei,” which translates to  “abortion will set you free,”  in a mock-up of the Nazi slogan over the gates of the Auschwitz-Birkenau death camp which reads “Arbeit macht frei,” or “work will set you free.”

Sven Lehmann of Germany’s Green Party has filed a criminal complaint against the bookstore. “Equating abortion with the Holocaust is thoroughly disgusting,” he wrote in a post on Facebook. “It relativizes the crimes the Nazis committed against millions of people.”

Lehmann added that “the decision to end a pregnancy is not an easy one.”

So far there has been no public response from the store owners.

Cologne Attorney General Ulf Willuhn told the Express.de online news agency that prosecutors are considering whether a criminal charge is possible on the basis of trivializing the Holocaust.

The Kindermord.org website and its backers condemn women who choose abortion, calling them participants in “the biggest ongoing crime in German history.”

The store’s ad campaign has come in for heavy criticism, including by the Rhineland Anti-Fascist Association Against Antisemitism and the Workers Community of Social-Democratic Women. The latter referred to the poster as “inhumane, Holocaust-relativizing and misogynistic. “