BERLIN (AP) — The mayor of Germany’s southwestern city of Tuebingen said Monday that he’s taking some “time out” after coming under fire over the weekend for using a racist slur.

Boris Palmer also said he’ll resign from the Green party following criticism over his repeated use of a racist term for Black people at a conference Friday, which prompted some attendees to walk out in protest.

Palmer was already suspended by the left-leaning Green party over his use of the slur in reference to a Black soccer player. Anti-racism activists gathered outside the event, a conference on migration hosted by Frankfurt University, and chanted “Nazis out” in response to his presence.

Palmer then repeatedly used the racial slur and suggested he was being victimised. “If someone uses the wrong word then they’re a Nazi to you,” he told the activists, and suggested that this reputation would stick with him like “the Star of David” that Jews were forced to wear during the Third Reich.

In Monday’s statement, Palmer apologised to “those I’ve disappointed” and said that a mayor “should never speak that way.” The 50-year-old, whose grandfather was Jewish, added that he’s “incredibly sorry” at having given the impression that he downplays the significance of the Holocaust.

Palmer said he would seek “professional help” to prevent himself from reacting inappropriately when he feels unjustly attacked in the future.

Palmer was first elected mayor of Tuebingen, population 90,000, in 2006 and won re-election running as an independent last year.