Chelbi, right, quit government a day after Mohammed Ghannouchi  resigned as Tunisia's prime minister [AFP]

Mohamed Afif Chelbi, Tunisia's industry and technology minister, has resigned from the government, the official TAP news agency has reported.

Chelbi, who resigned on Monday, was one of only two remaining ministers who had previously served in the cabinet under ousted President Zine al-Abidine Ben Ali.

His departure leaves Mohamed Nouri Jouini, the minister for international co-operation, as the only survivor in the cabinet from the Ben Ali era.

Protesters had demanded that Chelbi quit the interim government, led until the weekend by Ben Ali's prime minister Mohamed Ghannouchi.

Ghannouchi stepped down on Sunday following weeks of street protests.

He was swiftly replaced by 84-year-old Al-Baji Ca'ed al-Sebsi, a former minister who served under independent Tunisia's founding president, Habib Bourguiba.

Tunisia has been struggling to restore stability since Ben Ali, who had been in power for 23 years, was forced from office
in January by a wave of anti-government protests.

Protecting revolution

Protesters have been camping outside government offices in the capital Tunis, demanding that the government be purged of ministers with links to Ben Ali.

"We will continue our sit-in until the formation of a constituent assembly and the recognition of the Council for the Protection of the Revolution," Mohamed Fadhel, a protest co-ordinator, said.

Demonstrators are wary that the weeks-long uprising that ended Ben Ali's rule on January 14, and triggered revolts elsewhere in the Arab world, could be hijacked by members of the old regime still in positions of authority.

After leaving his post on Sunday, Ghannouchi said "I am not running away from responsibility ... This is to open the way for a new prime minister.

"I am not ready to be the person who takes decisions that would end up causing casualties," added the former prime minister, who had led Tunisia since Ben Ali fled the country.

"He's been under real pressure since he took over, and that pressure increased in the past 48 hours," Nazanine Moshiri, Al Jazeera's correspondent in eastern Tunisia, said on Sunday.

Protesters have also demanded the establishment of a parliamentary system. The interim government has meanwhile pledged elections by mid-July.