A leader of the German chancellor Angela Merkel’s conservative party has admitted that it has a problem with sexism in its ranks, after a female politician spoke out about vulgar and belittling comments.

Peter Tauber, the general secretary of the Christian Democratic Union (CDU), told the Bild am Sonntag newspaper that remarks made public by Berlin CDU politician Jenna Behrends were not an isolated incident.

“I hear about stories like these again and again, but without names. That makes it hard to do anything about it,” Tauber said. “We need a new sensitivity in all areas of society because sexism is not just a problem in politics.”

Behrends, 26, made national headlines last week when she spoke out against gender discrimination in the CDU, saying a member of the Berlin city-state’s government had called her a “big sweet mouse” in front of a group of people.

She said the same official asked another member of the party, using offensive language, whether he was having a sexual relationship with Behrends. She told Bild that she had received “a lot of positive feedback” for coming forward.

Merkel shattered party conventions when she, a childless, Protestant woman from the former communist East, became leader of the CDU in 2000 following a long line of Roman Catholic family men from the west.

The chancellor, who has led Germany since 2005, criticised German industry for failing to root out gender inequality on its own, in an interview with the business magazine Wirtschaftswoche on Sunday.

Citing the example of a quota introduced this year requiring Germany’s biggest companies to fill at least 30% of their supervisory board seats with women, Merkel lamented that executives in Europe’s top economy had to be forced into fair treatment. “It is pathetic that in more than 65 years of the Federal Republic of Germany, it was not possible for the Dax-30 companies to get a few more women on supervisory boards on a voluntary basis,” she said, noting she had long opposed statutory quotas. “But at some point there had been so many hollow promises that it was clear – this isn’t working.”

Merkel is expected to decide by the end of the year whether she will run for a fourth term as chancellor in the 2017 general election.