Tunisia's most prominent opposition figure quit the unity government Tuesday, further destabilizing the interim leadership amid renewed uncertainty about the country's direction.

Nejib Chebbi, who founded the opposition Democratic Progressive Party, said he resigned because he is not happy with the newly named prime minister and government measures he says are unjust and aimed at keeping him from seeking the presidency.

Tunisia's caretaker government is trying to restore stability and prepare for elections after weeks of protests drove out longtime President Zine El Abidine Ben Ali in January. The revolt sparked uprisings across the Arab world.

New protest violence in Tunisia in recent days left six dead, and the prime minister resigned under public pressure on Sunday. This raised new questions about the future of this country, long a haven for European tourists and ally in U.S. efforts to fight terrorism.

Chebbi said that the current instability in Tunisia could lead to a military takeover.

He said he is particularly frustrated by a measure requiring government ministers to abstain from running in upcoming presidential elections.

Chebbi is the latest of several government ministers to quit in the last two days.

The appointment of Chebbi and other opposition figures to the government days after Ben Ali's downfall was seen as a big step toward democracy in Tunisia, where dissent in politics and the media was routinely quashed for decades.

Chebbi's party, known by its acronym PDP, was long the primary legal opposition group in Tunisia. Many other opposition parties were banned.

Two more ministers left Tunisia's interim government Tuesday following the resignations of the prime minister and two other ministers after weeks of protests about the caretaker authority.

Higher education and scientific research minister Ahmed Ibrahim, head of Ettajdid party, told AFP that he had resigned believing he "could better serve the revolution by being outside of the government".

"The Ettajdid movement will have full freedom to act to contribute to the democratic transition," he said.

Mohammed Ghannouchi, prime minister in the interim government and for Ben Ali, quit on Sunday after clashes at weekend demonstrations left five people dead.

"I am not ready to be the person who takes decisions that would end up causing casualties," Ghannouchi said, announcing his decision to resign after just over six weeks as interim prime minister.

He was swiftly replaced as prime minister by 84-year-old Beji Caid Essebsi, a minister under independent Tunisia's founding president Habib Bourguiba.

Industry and technology minister Mohamed Afif Chelbi and planification and international cooperation minister Mohamed Nouri Jouini, who were both also in Ben Ali's regime, resigned on Monday.