Saxony's former premier, Kurt Biedenkopf of Merkel's own Christian Democratic party (CDU), slammed the chancellor's observation that she had not appointed an academic researcher to her cabinet, but a defence minister.
"The entire person has to be gauged, not just the office. And a person can't be split in two," he said. He echoed Bundestag speaker Norbert Lammert, also of the CDU, who called the plagiarism affair the "nail in the coffin" of the credibility of Germany's political class.
Parliamentary vice president Wolfgang Thierse from the centre-left Social Democrats also slammed Merkel for sticking to the defence minister, calling it akin to "schizophrenia."
"The chancellor is making a huge mistake if she thinks Guttenberg's fraud and his intellectual theft are not going to affect his office," he said. He accused her of dividing Guttenberg the private person from Guttenberg the minister.
"This kind of schizophrenia is completely unacceptable," Thierse said.
Voices from the world of academia have also grown increasingly critical of Guttenberg and Merkel. Oliver Lepsius, a legal scholar at the University of Bayreuth, where Guttenberg originally got his doctorate, has demanded the Minister's resignation.
"The academic community cannot accept these kinds of practices," he said. "If there are no consequences from the chancellor or the federal government, the relationship between science and politics is going to suffer appreciable damage."
When news of Guttenberg's plagiarism broke nearly two weeks ago, the minister played down the matter, calling the allegations “abstruse.” But just days later he dropped his Dr. title, admitting that he made “serious errors,” though unintentionally.
His alma mater, the University of Bayreuth, later officially stripped Guttenberg of the title.
The president of the Helmholtz Society, Jürgen Mlynek, had sharp words for the general handling of the affair.
"The public discussion of plagiarism and the general playing down of the matter concerns me greatly," he said. In the academic world, he added, "violations of rules against plagiarism generally carry penalties."