President Kais Saied has dissolved the Supreme Judicial Council.
He says the body that deals with judicial independence has become a thing of the past.
Saied had earlier plunged Tunisia into a constitutional crisis when he suspended the country's parliament, dismissed the sitting prime minister and granted himself executive powers.
The Democratic Forum for Labour and Liberties warned against the autocratic drift of Saied, denouncing a concentration of powers in his hands under the guise of a people's revolution.