The Strasbourg legislators demanded the immediate release of Noureddine Boutar, the director of Tunisia's largest independent radio station, saying he said had been arrested "on politically motivated grounds."
The European Parliament also called for the government to free "all others arbitrarily detained including journalists, judges, lawyers, political activists and trade unionists."
EU lawmakers said in a non-binding resolution they are "deeply concerned about President Saied's authoritarian drift and his instrumentalization of Tunisia's dire socio-economic situation," a statement said.
"MEPs call for an end to the ongoing crackdown on civil society in the country," the parliament said.
The EP urged the EU to cut support programs to Tunisia's justice and interior ministries over the deterioration in human rights.
The lawmakers in addition slammed Saied for his "racist discourse against sub-Saharan migrants," condemning attacks that have ensued against them.
Saied sacked the government and froze parliament in a 2021 power grab before imposing sweeping changes to the political system of the sole democracy to have emerged from the Arab Spring uprisings.
More than 20 political figures have been arrested in the North African country in recent weeks, including members the of the main opposition coalition.