Ali Larayedh became Tunisia's new Islamist premier on Thursday, taking over from his predecessor Hamadi Jebali and faced with the task of ending a political and economic crisis gripping the country.
Speaking at the swearing in ceremony at the prime minister's office, Larayedh said his cabinet would listen to "the concerns of the nation and the people."
Larayedh was speaking a day after his coalition received parliament's backing in a vote of confidence, and just hours after the funeral of a street vendor whose self-immolation served as a stark reminder of the problems facing the new government.
Larayedh has already promised to resolve Tunisia's institutional crisis this year, by ensuring the adoption of a new constitution and organising elections, while creating the conditions for an economic recovery and restoring security.
Jebali, who failed to win his Ennahda party's approval for the technocrat administration he had proposed after last month's assassination of opposition leader Chokri Belaid, endorsed the team of his successor and fellow Islamist.
"Those who are hoping for the failure of the (new) government are hoping for the failure of the (democratic) experience" in Tunisia, Jebali said.
Earlier, mourners at the funeral of Adel Khazri, a 27-year-old street vendor who died on Wednesday after setting himself on fire in central Tunis, shouted slogans denouncing Larayedh's ruling Islamist party.
"Ennahda, get out!" they chanted during the funeral in the impoverished town of Souk Jemaa in northwestern Tunisia, which was attended by several hundred people, according to an AFP journalist.
Khazri, who supported his family by selling contraband cigarettes, had arrived in the capital a few months ago to look for work.
His death revived the haunting memory of Mohamed Bouazizi, another street vendor who burned himself to death in December 2011 in protest at his precarious living conditions, sparking the uprising that toppled ex-dictator Zine El Abidine Ben Ali.
Larayedh's new cabinet, formed after weeks of fraught political negotiations and uncertainty triggered by the killing of Belaid, is an awkward alliance grouping Ennahda, two secular parties and independent technocrats.
Tunisian media on Thursday highlighted the daunting political, social and economic challenges the government faces, with one newspaper warning that it was "not entitled to make mistakes."
La Presse, a French-language daily, said the government had to pull Tunisia out of a "vicious circle" and must "relaunch investment to create jobs, with unemployment creating the instability in the country that is deterring investors."
Tunisia is struggling to revive its economy and confront the social woes afflicting it two years after the revolution, with unemployment and poverty still major sources of discontent.
In a brief interview with AFP on Wednesday, Larayedh said the principle threats facing Tunisia were "terrorism" and social unrest.
"The main danger to national security is terrorism, whether it comes from abroad or from inside the country," he said, adding that another threat was "social violence fed by politics."
In addition to economic hardships and the political turmoil caused by the killing of Belaid, an outspoken critic of the ruling Islamists, a wave of violence blamed on hardline Salafists has rocked Tunisia since the revolution.
The authorities have accused the radical Islamists of Belaid's murder and made a number of arrests, but the suspected killer remains at large.
Tunisia also remains without a fixed political system because of a lack of consensus between the main parties, with Ennahda pushing for a pure parliamentary system while others are demanding that the president retain key powers.
Parliament is due to vote on a timetable for the adoption of a new constitution, after a proposal was submitted on Monday that the charter be adopted in July, and elections held in October.
But some have insisted those dates are unrealistic, given previous failures.