Schalke chairman Clemens Tönnies before a game last season.
CNN  — 

The chairman of a leading German football club is under growing pressure to resign after making racist comments about African people during a speech last week.

Schalke chairman Clemens Tönnies criticized tax increases to fight climate change while speaking at a festival in the western city of Paderborn, suggesting instead that money be used to fund power plants in Africa.

“Then the Africans would stop cutting down trees and stop producing children when it’s dark,” Tönnies was quoted as saying by regional German newspaper Neue Westfälische.

He has since apologized for his remarks and said he supports Schalke’s values against “racism, discrimination and exclusion.”

The club told CNN that their ethics body will be discussing his remarks soon, in an upcoming meeting.

“I would like to explicitly apologize to you, the fans, members and friends of FC Schalke 04,” Tönnies said in a statement on the club’s website. “It was wrong, thoughtless … and in no way met our mission statement. I am very sorry.”

But politicians and some fans of the Bundesliga club have urged him to quit, and the German Football Association (DFB) is under pressure to discipline the businessman.

Germany’s Justice Minister Christine Lambrecht has led calls for Tönnies’ comments to be punished. “Racism must be loudly and clearly contradicted,” she told newspapers of the Funke media group.

“Nowhere is integration as successful and quick to work as in sport – that must not be put at risk,” Lambrecht added.

SDP lawmaker Markus Töns said on Twitter: “The racist statement by Clemens Tönnies at the “Day of Crafting” in Paderborn is incompatible with the mission statement of Schalke 04.”

And Dagmar Freitag, who chairs the sports committee in Germany’s parliament, argued that Tönnies’ apology cannot make up for the damage his remarks caused.

“That something like this (is) articulated by someone who holds a prominent position in the sport makes things even worse,” she told German newspaper Welt, adding that his explanation “certainly can not make up for the socio-political damage.”

CNN has asked the DFB for comment.

Schalke start their Bundesliga season on August 17. Last season, they finished 14th in Germany’s top division.