The artist Markus Lüpertz has won a commission to create a multipart mural depicting the story of Genesis in the subway stations of the German town of Karlsruhe. After months of heated debate, the city council gave the project the green light on Tuesday. But not everyone is pleased with the decision.

Anton Goll, a former ceramics manufacturing executive, campaigned to have the artist transform advertising spaces in the city’s seven underground stations into a series of large-tiled ceramic mosaics presenting the creation story.

The stations—which are currently under construction—are scheduled to be finished in four years. Goll has said that the privately financed project has already raised half of the estimated €1 million ($1.1 million) budget from donors and sponsors, according to the German press agency DPA.

Karlsruhe’s mayor called the proposal “highly interesting” and said the public artworks “could be an image gain” for Karlsruhe. But several residents have raised concerns over the public presentation of religious imagery, which they say is incongruous with a secular, multiethnic society.

In an open letter published on Tuesday, Peter Weibel, the director of Karlsruhe’s Center for Art and Media (ZKM), said that the “ceramic church art” would be bad for the public image of a city trying to market itself as modern, tech-friendly, and progressive. He wrote: “How can it be that centuries-old denominational art is not shown in churches, as has been customary, but that religious myths are presented in public spaces simply because a few people are able to finance it?”

Meanwhile, the city’s Green Party has taken issue with the lack of public discussion surrounding the proposal. The party’s members voted against the project in yesterday’s town council vote. Councillor Renate Rastätter of the Green Party told DPA: “The question is, how do we deal with art in public spaces?”