Efforts to resolve one of the worst crises Tunisia has faced since the revolution have faltered as the Islamist party dominating the ruling coalition rejected a bid to form a non-partisan government.
The crisis was sparked by the killing of Chokri Belaid, a fierce government critic, who was shot several times in his car just outside his home on Wednesday by unknown attackers.
Demonstrations erupted around the country and were quelled by tear gas. Prime Minister Hamadi Jebali announced later that he would dissolve the government and form a new one of technocrats to manage the country until elections - a long-standing opposition demand that was widely welcomed.
The next day, however, the vice president of the Islamist Ennahda, Abdel-Hamid Jalasi, said the party disagreed with the move, throwing the political future of the country into question once more.
Tunisia's Radio Mosaique meanwhile reported full-scale riots in the southern mining city of Gafsa, where Mr Belaid's Popular Front coalition of leftist parties has a great deal of support. Demonstrators marched through the city and threw stones at police, who responded with tear gas. The capital Tunis, however, remained quiet amid cold weather and a heavy downpour.
Mr Jalasi, according to Ennahda's website, said the country still needed political figures to run it and suggested returning to the long-running talks with other parties to expand the government. He added that the party was not informed of the prime minister's move before it happened.
Ennahda was long repressed by Tunisia's dictator Zine El Abidine Ben Ali, but after his overthrow in January 2011, the well-organised movement dominated subsequent elections and now rules in coalition with two secular parties.
Relations between the government and the opposition had deteriorated in recent months and talks over a government reshuffle had gone nowhere.
Meanwhile, critics like Mr Belaid accused the government of employing thugs to attack meetings of the opposition. Mr Belaid's family and associates blame the Islamist-dominated government of the Ennahda Party for complicity in the assassination, and other opposition figures have claimed there is a list of potential targets.
Opposition parties had hailed Mr Jebali's initiative as a courageous decision. The year-old government has often been criticised for being unable to tackle the country's problems, chief among them high unemployment and an economy battered by Europe's financial crisis and too few tourists.