Senior members of Tunisia's former ruling party will be banned from a 24 July election and the vote will be run by an independent body for the first time, Prime Minister Beji Caid Sebsi said on Tuesday.

After the ousting of President Zine Al-Abidine Ben Ali in a "Jasmine Revolution" that triggered upheaval across the Arab world, interim authorities have announced the ballot for a new assembly to rewrite the North African country's constitution.

Sebsi said those who held senior positions in Ben Ali's former Constitutional Democratic Rally (RCD) party for the past decade would be barred from contesting. So would all Ben Ali's former advisors.

"We are going to prepare a list of the names of these people," Sebsi told a news conference in Tunis.

Ben Ali was toppled by mass protests on 14 January after 23 years in power and fled to Saudi Arabia. Since then, a judge has ruled that the former ruling party is to be disbanded and its funds seized.

An advisory council set up after Ben Ali was overthrown had recommended the ban on top RCD members from the election, but it has only now become policy.

Interim authorities in the Mediterranean country of more than 10 million people scrapped Ben Ali's feared state security apparatus and appointed a new government on 7 March to carry out political reform and a transition to democracy.

"For the first time, an independent committee will run the elections," said Sebsi. "This is the first time that government will not interfere in elections."

Ben Ali won nearly 90 per cent of the vote in the last presidential election in 2009 -- slightly down on his margin of victory five years earlier. Tunisia's main opposition figures did not contest a poll they dismissed as a farce.

The Organisation for Security and Cooperation in Europe, Europe's main rights and security watchdog, says Tunisia has made a good start in its transition to democracy but faces a challenge to meet people's expectations of rapid progress.