The leader of Germany's liberal Free Democrats party has likened Turkish President Recep Tayyip Erdogan's purge of state institutions to the actions of the Nazi party in the 1930s.
Mr Erdogan has tightened his grip on the country since a failed coup last month, ordering the closure of thousands of private schools, charities and other institutions.
Thousands of people he has linked to a US-based cleric he blames for the failed putsch, have been arrested.
FDP (Free Democrats) leader Christian Lindner said Mr Erdogan was building an authoritarian regime tailored solely to himself.
Mr Lindner said he saw parallels between Mr Erdogan's behaviour and aftermath of the Reichstag fire in 1933, portrayed by the Nazis as a Communist plot against the government and used by Adolf Hitler to justify massively curtailing civil liberties.
"We are experiencing a coup d'etat from above like in 1933 after the Reichstag fire. He is building an authoritarian regime tailored solely to himself," Mr Lindner told the Bild am Sonntag newspaper.
"Because the rights and freedoms of the individual no longer play a role, he cannot be a partner for Europe," he added.
His comments echo those of Austria's far-right Heinz-Christian Strache who said on Saturday that Mr Erdogan's use of the failed putsch in July to crack down on his opponents was reminiscent of Hitler's use of the Reichstag blaze to amass greater power.
Mr Erdogan has angrily rejected suggestions that he or his government might have been behind the failed coup, which he has blamed on the followers of a US-based Muslim cleric.
The FDP are not currently represented in Germany's Bundestag but have previously governed as a junior coalition partner to Chancellor Angela Merkel's conservatives (CDU) and are a potential ally for them after federal elections in autumn 2017.
However, Mr Lindner criticised Mrs Merkel's response so far to the crackdown on Mr Erdogan's opponents in the army, civil service, academia and media.
"It disgusts me that the EU accession talks (for Turkey) have not been ended long ago. But Mrs Merkel is only cautiously urging 'proportionality'," he said.
Germany's foreign minister on Friday resisted a push by Austria to halt the talks with Turkey on joining the European Union, saying the bloc needed to think more broadly about how to frame its relationship with Ankara in troubled times.