German Education Minister Annette Schavan has resigned after a university stripped her of her doctorate for plagiarism.

Duesseldorf’s Heinrich Heine University voted last Tuesday to remove her doctorate following a review.

Ms Schavan, a close ally of Chancellor Angela Merkel, insisted she would still fight the university’s ruling.

In 2011, Defence Minister Karl-Theodor zu Guttenberg also quit after allegations he plagiarised his thesis.

Ms Schavan, 57, was awarded her doctorate 33 years ago, but the university found she had “systematically and intentionally” copied parts of her thesis Person and Conscience.

She had been scathing in her criticism of Mr Guttenberg when the scandal of his plagiarism broke.

Analysts say her resignation will be hugely embarrassing to Mrs Merkel.

The chancellor is facing federal elections on 22 September.

She said she accepted the resignation “with a heavy heart”.

Part of Ms Schavan’s brief as education minister is to oversee German universities.