A political meeting of the party on the resort island of Djerba was besieged by hundreds of alleged members of the leagues on Dec. 23, according to party members.

In the face of what it describes as a lack of government concern, Nida Tunis has threatened to file a suit against the leagues with the International Criminal Court for crimes against humanity.

The most serious incident involving the leagues, however, came in early December, when men described as being part of the leagues assaulted with clubs and stones a march at the main union headquarters in the capital Tunis.

The powerful union, which has emerged in recent months as a focus of opposition to the government, threatened to shut the country down with a general strike until a compromise deal was finally struck. Jourchi, the analyst, warned that the leagues are ‘‘becoming a factor for instability,’’ pointing out that their job of ‘‘protecting the revolution,’’ should be the business of the state.

As part of the ceremonies marking the anniversary, the government and union leaders signed a ‘‘social pact’’ Monday promising to boost the economy and end the destructive strikes.

The rise of violence and internal tensions in Tunisia couldn’t come at a worse time as the situation outside its borders deteriorates, with al-Qaida newly active in the Sahara, partly fueled by the weapons pouring out of Libya’s civil war. In December, police reported finding two militant training camps near the Algerian border, likely to prepare disaffected Tunisians to join the jihads south in Mali or neighboring Algeria.