Tunisian Prime Minister Ali Larayedh Monday called a general election for December 17 after an emergency meeting aimed at easing political tensions and as protests demanded the Islamist government's ouster.
"This government will stay in office: we are not clinging to power, but we have a duty and a responsibility that we will exercise to the end," he told state television, proposing December 17 for a general election.
Larayedh made the announcement after a cabinet meeting and a security meeting chaired by President Moncef Marzouki.
"We think that the National Constituent Assembly will complete the electoral code by October 23 at the latest so elections can be held on December 17," he said.
Larayedh estimated that 80 percent of the work in adopting a new constitution had already been completed.
December 17 is a significant date: it was on that day in 2010 that fruit vendor Mohamed Bouazizi burned himself alive in the town of Sidi Bouzid, beginning the Tunisian revolution.
"The government is not incapable of calling for popular support to discover whether the people are with this government or with those who want to take it backwards towards the unknown," Larayedh said.
He spoke after protests mounted demanding the government's ouster and police clashed with stone-throwing demonstrators in Sidi Bouzid.
Tensions have frayed across Tunisia.
None more so than in Sidi Bouzid, cradle of the uprising that toppled strongman Zine El Abidine Ben Ali, and home town of an anti-Islamist MP who was assassinated on Thursday.
Mohamed Brahmi was the second opposition politician killed after Chokri Belaid was gunned down outside his home in February.
Many Tunisians blame the government for both killings.
Government detractors say the Ennahda-led cabinet has failed to rein in radical Islamists who have grown in influence and stand accused of a wave of attacks since the 2011 uprising.
On Monday morning, anti-government protests erupted in both Tunis and Sidi Bouzid, with demonstrators demanding the resignation of the government and the dissolution of parliament.
In both cities, police used tear gas against protesters, AFP correspondents reported.
In the centre-west city of Sidi Bouzid, they fired tear gas to disperse stone-throwers among a crowd of hundreds of protesters who blocked employees from going to work at the governor's office.
"Ghannouchi, assassin!" the crowd chanted in reference to Ennahda party leader Rashid Ghannouchi.
Demonstrators demanded the dismissal of the governor, who is regarded as close to the Islamists.
In Tunis, police fired tear gas to disperse a rally outside the National Constituent Assembly for a fourth day running.
Overnight around 10,000 people demonstrated for and against the government on Bardo Square outside parliament, separated by police vans and metal barricades.
Protests have swelled at night in Tunis, where streets are empty during the day because of searing temperatures and the dawn-to-dusk fast observed by the faithful during the Muslim holy month of Ramadan.
Protesters chanted: "The people want the fall of the assassins," while across the barricades government supporters retorted: "The people are Muslim and will not capitulate".
"Those who boycott the NCA betray Tunisia," Ennahda MP Fathi Ayadi told AFP.
NCA speaker Mustapha Ben Jaafar has called for "restraint" and urged deputies to return and resume work on the much-delayed constitution, one of the thorniest issues in post-revolution Tunisia.
Dozens of MPs have been boycotting parliament since Brahmi's murder.
Authorities have accused radical Salafists close to Al-Qaeda-linked group Ansar al-Sharia of killing Brahmi, whose body was riddled with 14 bullets outside his home.
They say the same gun was used to assassinate Belaid in February.
Ansar al-Sharia denied any responsibility.
Hundreds of thousands of mourners thronged the streets of Tunis on Saturday for an emotionally charged funeral procession to El-Jellaz cemetery, where Brahmi was buried next to Belaid.
Anti-government protesters then assembled outside the NCA and clashed with police, who again fired tear gas.
Interior Minister Lotfi Ben Jeddou has since pledged to guarantee the safety of anti-government demonstrators, leftist MP Samir Taieb said after meeting the minister.
Taieb, who has called on the government to step down and hand over to a national unity administration, said nearly a third of the 217 members of the assembly were boycotting its sessions.