Tunisia's Islamists plan a comeback after the dramatic ouster of Zine El Abidine Ben Ali but know they need to tread softly in a largely secular society where some are already worried about their role.

Banned under Ben Ali's 23-year regime, its members jailed or exiled, the Islamist movement Ennahdha was on the sidelines of the Jasmin Revolution that climaxed with the disgraced president's escape to Saudi Arabia last Friday.

But on Tuesday, for the first time in a month of protests, the group emerged with a protest in the capital led by its ex-president Sadok Chourou against the dominance of Ben Ali ministers in the new transitional government.

It was just a start, with the movement planning to regather and reapply for legal status, said one of its leaders, Ali Laraidh, who was imprisoned for 14 years under the old regime for plotting against the state.

"We expect to make a request on these lines," he said. "If democracy is installed, we will be a party like all the others, we will have our rights and our duties."

But that will have to wait until there is a general amnesty to allow the return of exiled Ennahdha (Awakening) members, including its leader Rached Ghannouchi based in London.

Founded in 1981 by intellectuals inspired by the hugely influential Muslim Brotherhood born in Egypt, Ennahdha was at first tolerated in Tunisia including in the initial years after Ben Ali took power in 1987.

Things changed after the 1989 parliamentary election, when the Islamists ran as independents because they had consistently been refused legalisation and managed to secure 17 per cent of the vote.

With Ben Ali's party clamping down, Ennahdha members were accused of violence and involvement in an Islamic fundamentalist plot against the state, and scores were rounded up and jailed.

Prime Minister Mohammed Ghannouchi, no relation to the Ennahdha leader, has already promised the end of bans on political groups like the Communists and Islamists, among a host of unprecedented new freedoms.

But he has said Rached Ghannouchi would only be able to return once a planned amnesty law is passed because of his life sentence for plots against the state.

Ghannouchi would not run for presidential elections to be held within six months, but the movement would stand for the parliamentary elections, a movement spokesman said in Paris.

"We are ready to consult with everyone, all political forces and civil society," said the spokesman, Houcine Jaziri.

"There has been in Tunisia a people's revolution which has reclaimed social and political rights. We do not want to appear to have hijacked this movement," he said.

Ennahdha's reemergence has not yet met with much reaction in Tunisia, with rights activist Mouhieddine Cherbib categorising them as "Islamists of the AKP sort" -- a reference to Turkey's moderate Justice and Development Party (AKP), the ruling party.

He believed they could not achieve much, with little profile amongst the youth and secular Tunisia not fertile ground for such a group.

"In the demonstrations, the demands were not for Islam but for democracy and freedom," said Cherbib.

He admits though that while "some see them as moderates, others see them as the Islamist wolf on the prowl."

Political analyst Larbi Chaouikha was among those who are hesitant.

"The moment we declared democracy, nothing could prevent their existence as a recognised political party. But as a secular activist, I have worries," he said.

"Is Ennahdha ready... to respect the rights of women, the separation between religion and politics, in short universal values of human rights?" he asked.