Human Rights Watch has called on Tunisia to abolish "repressive" laws that "silence criticism and dissent" after a blogger was jailed for three-years for criticising the army in a series of Facebook posts.

The New York-based group called on Tunisia's parliament to change the mandate of military tribunals on Tuesday as Yassine Ayari, a France-based Tunisian national, was scheduled to re-appear in court over allegations of insulting the military.

Repressive laws like article 91 of the military justice code should have no place in a country where basic human rights are the foundation of its new constitution Eric Goldstein, Human Rights Watch

Ayari, who was convicted in absentia by a military court on November 18, published several Facebook posts in August and September criticising Minister of Defence, Ghazi Jeribi.

The judge presiding over the case said Ayari’s posts had defamed the army command and could harm the "morale" of the armed forces.

In another trial on November 18, the same military court sentenced Sahbi Jouini, a police union leader, to two years in prison under the same article of the military justice code concerning defamation.

"In a single day, Tunisia’s military court imposed prison sentences on a union leader and a blogger for speech offenses, even though neither was present for his trial" Eric Goldstein, deputy Middle East and North Africa director at Human Rights Watch said in a statement. "This is not worthy of the new Tunisia."

International law prohibits the trial of civilians before military courts.

Article 91 of Tunisia's code of military justice authorises up to three years imprisonment for anyone who "commits... outrages against the flag or the army, offenses against the dignity, reputation or morale of the army, or acts to undermine military discipline, obedience and due respect to superiors or criticises the action of military hierarchy or the military officers, offending their dignity".

"Repressive laws like article 91 of the military justice code should have no place in a country where basic human rights are the foundation of its new constitution," Goldstein said. "As long as such laws remain, those in power can’t resist the temptation to silence criticism and dissent."

Human Rights Watch called on Tunisia's parliament to reform all laws that lead to prison terms for offenses that involve defaming or insulting state institutions.

They should also change the mandate of the military tribunals to remove jurisdiction of military courts over civilian defendants, it added.

Tunisia completed its political transition with a string of elections in late 2014, four years after mass protests swept longtime leader Zine El Abidine Ben Ali from power.