A Tunisian investigative judge ordered on Thursday the imprisonment of the leader of Ennahda party Rached Ghannouchi, the prominent critic of President Kais Saied, the politician’s lawyer told Reuters.

The move against Ghannouchi, who was arrested on Sunday, came on suspicion of plotting against internal state security, after an investigation that lasted eight hours, she added.

“It was a ready decision to imprison Ghannouchi only because of Ghannouchi’s expression of his opinion,” lawyer Monia Bouali told Reuters.

Ghannouchi’s official Facebook page published a comment by him after the judge’s decision, which said: “i am optimistic about the future.”

Tunisian authorities on Tuesday banned meetings at all offices of the opposition Ennahda Islamist party and police closed the headquarters of the Salvation Front main opposition coalition.

Ennahda fears the move will pave the way for banning the party and comes a day after police detained Ghannouchi and three senior officials, the party said.