Rached Ghannouchi attends an interview with Reuters at his office in Tunis
Rached Ghannouchi, the head of Islamist Ennahda party and former speaker of the parliament, during an interview with Reuters at his office in Tunis, Tunisia, July 15, 2022. Reuters

A Tunisian judge on Thursday ordered opposition leader Rached Ghannouchi be detained before his trial on charges of plotting against state security, the latest escalation of a crackdown against opponents of the president, his lawyer told Reuters.

The 81-year-old, head of the Islamist Ennahda party, was the speaker of the elected parliament, which was shut down in 2021 by President Kais Saied when he seized all powers.

Ghannouchi, who was arrested on Monday, was ordered detained following an investigation by the judge that lasted eight hours, lawyer Monia Bouali added. No date has been set for any trial or the next hearing.

Ennahda condemned the "unjust decision" and said it was intended to cover up failure in a stifling economic and financial crisis that is leading the country towards bankruptcy.

It said that targeting a "national symbol" who has spent decades resisting dictatorship would not resolve Tunisia's problems and would not weaken the opposition.

Ghannouchi's official Facebook page published a comment by him after the judge's decision which said: "I am optimistic about the future ... Tunisia is free."

His lawyer said the decision to hold Ghannouchi in custody was pre-planned because of his expressions of opinion.

Police have this year detained several leading political figures who have accused Saied of a coup for his moves to close parliament and rule by decree before rewriting the constitution.

Saied says his actions are legal and necessary to save Tunisia from chaos, and has called his enemies criminals, traitors and terrorists, urging the authorities to take action against them.

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

Ennahda says it fears the move could lead to it being banned.

Since Tunisia's 2011 revolution, Ghannouchi has been a major political player, leading his party to participate in successive coalition governments with secular parties.

He has faced repeated rounds of judicial questioning over the past year on charges relating to Ennahda's finances and to allegations it helped Islamists travel to Syria for jihad, charges he and the party deny.

The United States has said Ghannouchi's arrest, the closure of Ennahda's headquarters and the banning of meetings by opposition groups represented a troubling escalation.

An interior ministry official said Ghannouchi had been arrested after "inciting statements".

Ghannouchi said in an opposition meeting last week that "imagining Tunisia without this or that side ... Tunisia without Ennahda, Tunisia without political Islam, without the left, or any other component, is a project for civil war".

The influential leader, who was in exile in the 1990s and returned after the revolution that brought democracy to the country, said those who celebrated what he called a coup could not be democrats.