(CNN) -- Prime Minister Hamadi Jebali said Saturday he would step down if the caretaker government he is forming fails to win approval from Tunisia's National Constituent Assembly.
Jebali's statement to the media came amid political instability after the assassination Wednesday of an opposition leader.
In response to the shooting death of Chikri Belaid, Jebali sacked his government and said he would appoint a new one to serve until the next election.
However, a top official of Jebali's own Ennahda party labeled Jebali's moves "non-binding," raising questions about the solvency of his leadership.
On Saturday, Jebali said he would remain as prime minister if the National Constituent Assembly accepts the new government he will propose.
If the assembly, which includes his moderate Islamist party, rejects the caretaker government, Jebali said he will ask the country's president "to designate another candidate to form a new government" likely to get the body's approval.
A day earlier, Jebali denied that Ennahda had anything do with Belaid's killing and said he hoped to get approval for his new government from his party and others.
"The government, I feel, is backed by a lot of people, mainly among ordinary people. I hope that political parties will translate the view of our people," Jebali said.
As he spoke Friday, thousands of Tunisians demonstrated in the streets of the capital in outrage over the assassination, calling on Jebali to resign.
The killing of Belaid was the country's first high-profile political assassination since Tunisia's "Jasmine Revolution" that toppled President Zine alAbidine Ben Ali two years ago and spawned the Arab Spring.
Jebali urged calm Friday, saying violence and political instability was the goal of the assassins, who he said wanted to undermine the Jasmine Revolution.
He defended the current leadership's role in supporting the changes brought by the revolution in this North African country of nearly 11 million people.
"Tunisian people made the Jasmine Revolution for two goals: revolution against dictatorship and revolution against corruption, and they also wanted social justice," he said.
Those goals have not been betrayed, Jebali said,adding that "the biggest proof is what is happening in the streets -- protests, free press."
"We are not corrupt people, but if people made a revolution against us, that's their right, and we will bow to the will of our people," he said.
Also Friday, tens of thousands of mourners followed Belaid's funeral cortege as his flag-draped casket was taken through the streets of the capital to a cemetery. A phalanx of uniformed soldiers escorted the coffin bearers into the cemetery.
At times, protesters clashed with security forces, who fired tear gas into the crowds. A private TV channel broadcasting the procession showed a car burning.
Many of those mourning Belaid expressed anger at the government, which they accuse of allowing a climate of political violence to spread unchecked.
Belaid, a prominent secular politician who decried violence, was shot dead as he left his home Wednesday morning for work. No one has claimed responsibility for the attack, but Belaid's widow and others blamed the climate fostered by Jebali's governing Ennahda party.
Meanwhile, the first general strike by Tunisia's trade unions in three decades closed shops, cafes and other businesses Friday. The national airline, Tunisair, warned of possible flight disruptions.
Protests also have erupted in the central towns of Gafsa and Sidi Bouzid, the birthplace of the revolution.
Belaid, whose party was the secular-leftist Democratic Patriots, also was the voice of a coalition of secular opposition parties known as the Popular Front.
He routinely received death threats for his criticism of Tunisia's moderate Islamist-led government. He talked about the threats on his frequent television appearances, but said he didn't fear for his life.
Official investigators have yet to reach a conclusion on who may have been responsible.
Amna Guellali of Human Rights Watch said the government bears some responsibility because of its "laxity" in failing to respond to a climate of rising political violence.
"We warned the government that these incidents of violence should be investigated thoroughly and that people who have perpetrated these acts should be punished ... but we haven't heard anything back," she told CNN in Tunis.
Guellali cited calls by preachers in some mosques in July for the killing of certain Tunisian political figures and personalities, including Belaid.
"We didn't see the government reacting to these calls of clear incitement to murder," she said. "A government has to protect its citizens ... especially if there are clear threats against this person."
CNN's Dan Rivers, Laura Smith-Spark and Joseph Netto contributed to this report.