German Defence Minister Karl-Theodor zu Guttenberg has stepped down after he was found to have copied large parts of his 2006 university doctorate thesis.
Mr Guttenberg, considered until recently a possible candidate for chancellor, has already been stripped of his PhD.
He told a news conference that it was "the most painful step of my life".
Tens of thousands of German academics have written to Chancellor Angela Merkel complaining about his conduct.
The plagiarism scandal led to him being nicknamed Baron Cut-and-Paste, Zu Copyberg and Zu Googleberg by the German media.
But Ms Merkel had continued to stand by him, with her party facing three state elections later this month.
Mr Guttenberg told reporters in Berlin that he was relinquishing all his political offices and he thanked the chancellor for her support, trust and understanding. BBC News
