Germany's education minister has resigned after a university decided to withdraw her doctorate, finding that she plagiarised parts of her thesis - an embarrassment for Chancellor Angela Merkel's government as it prepares for elections later this year.
Mrs Merkel said she had accepted "only with a very heavy heart" the resignation of Annette Schavan, who has been her education and research minister since 2005 and was considered close to the chancellor.
On Tuesday, Duesseldorf's Heinrich Heine University decided to revoke Ms Schavan's doctorate following a review of her 1980 thesis, which dealt with the formation of conscience. The review was undertaken after an anonymous blogger last year raised allegations of plagiarism, which the minister denies.
"I will not accept this decision - I neither copied nor deceived in my dissertation," she told reporters, speaking alongside Mrs Merkel at a brief news conference. "The accusations ... hurt me deeply."
Ms Schavan made clear that she was going to prevent the issue turning into a festering problem for her party, and the government, as Germany gears up for parliamentary elections on September 22 in which the conservative Mrs Merkel will seek a third term.
Ms Schavan, a member of Merkel's Christian Democratic Union, announced her decision after returning from an official trip to South Africa during which, she said, she thought "thoroughly about the political consequences".
"If a research minister files a suit against a university, that of course places strain on my office, my ministry, the government and the CDU as well," she said. "And that is exactly what I want to avoid."
Mrs Merkel offered lengthy praise of Ms Schavan's "exceptional" performance as a minister, adding that "at this time, she is putting her own personal well-being behind the common good".
Ms Schavan will be replaced by Johanna Wanka, the outgoing regional education minister in the state of Lower Saxony, Mrs Merkel said. That state's conservative-led government narrowly lost a regional election to the centre-left opposition last month.
Ms Schavan's resignation comes two years after then-Defence Minister Karl-Theodor zu Guttenberg lost his doctorate and quit when it emerged that he copied large parts of his doctoral thesis. Doctorates are highly prized in Germany, where it is not unusual for people to insist on being referred to by their full academic title.