Fahrat Rajhi suspended all meetings of the Democratic Constitutional Rally, known as the RCD, and ordered all party offices or meeting places it owns closed and intends to seek its dissolution, a ministry statement said.
The official TAP news agency, which carried the statement, said the measure was taken because of the "extreme urgency" of the situation, a reference to deadly protests, and to "preserve the higher interests of the nation."
The announcement came hours after crowds pillaged, then burned a police station in the northwestern city of Kef a day after police shot and killed at least two demonstrators.
It was the worst violence in Tunisia since its autocratic president, Zine El Abidine Ben Ali, was forced into exile Jan. 14 after a month of nationwide anti-government protests.
Deadly protests have also erupted in other corners of this North African country, currently run by a caretaker government.
Authorities have been cleaning out traces of the Ben Ali regime, notably eliminating figures connected with the former ruling party - but not fast enough for many citizens. The RCD's activities were not just limited to the political scene. Under Ben Ali's 23 years in power, the party had tentacles in all aspects of Tunisian life.
Among other distrusted entities is the police force, which instilled fear as it carried out the repressive policies of Ben Ali. The move by the interior minister, ultimately in charge of police, could amount to a double gesture to shore up the "people's revolution" in the eyes of many Tunisians.