German Chancellor Angela Merkel suffered a major political blow less than eight months before elections when her education minister, a close ally, resigned on Saturday, Feb 9 over plagiarism allegations, AFP reported.

Merkel said she had accepted the resignation of Annette Schavan "with a heavy heart" after her former university stripped her of her doctorate, saying she had plagiarized parts of her thesis "Person and Conscience" 33 years ago.

Schavan reiterated her vow to fight the allegations but said she did not want the claims to damage the office, the party or the federal government.

"I think today is the right day to leave my ministerial post and to concentrate on my duties as a member of parliament," said a visibly moved Schavan.

Merkel said she had suggested to the country's president that Johanna Wanka, a minister in the state of Lower Saxony, should succeed her.

Schavan, 57, became the second close ally of Merkel to step down over plagiarism after Karl-Theodor zu Guttenberg, a popular defence minister, sometimes tipped as a future chancellor, resigned in 2011.

The extent of Schavan's alleged plagiarism is thought to be less than that of zu Guttenberg's, whose actions earned the aristocrat the nicknames "Baron cut-and-paste" and "zu Googleberg".

Nevertheless, Schavan's mistakes were seen as indefensible given her position as education minister in a country where academic titles are taken extremely seriously.

There was also an element of schadenfreude given her reaction to zu Guttenberg's downfall, when she said she was "ashamed" of her former cabinet colleague.