Delegates began gathering Saturday for the launch of a hard-won dialogue between Tunisia's ruling Islamists and the opposition aimed at ending a crisis protracted political crisis.

The conflict was triggered in July with the assassination of prominent MP Mohamed Brahmi, with the opposition accusing Islamist Ennahda party of failing to curb extremists they say were behind the murder.

Delegates began gathering at the Palais des Congres for Saturday highly-symbolic ceremony, during which Ennahda must solemnly declare its willingness to resign and, along with the opposition, pledge allegiance to a roadmap on the country's political future.

The talks, which will begin in earnest next week and last a month, will focus on implementing the roadmap that calls for the formation of a government of independents, the adoption of a much-delayed constitution and set a timetable for new elections.

"The presidents of the various political parties will sign on today" to the roadmap, the head of the Tunisian League for Human Rights, Abdessatar Ben Moussa, told AFP.

"Ennahda must pledge the government's resignation," he added

The League is among four groups which drafted the roadmap and mediated an agreement between Ennahda and the opposition to launch a national dialogue to implement its terms.

Earlier this week, Ennahda and the secular opposition agreed to a blueprint for talks drafted by the League, the main UGTT trade union and the employers' organisation Utica.

The roadmap sets a three-week deadline to form a cabinet of independents to replace the government, after the launch of a dialogue with opposition parties.

It also sets a four-week deadline for adopting a new electoral law, announcing a timetable for fresh elections and completing a long-delayed draft constitution.

Ennahda has also been accused of mismanaging the economy and failing to rein in Tunisia's jihadist movement, which is blamed for murdering Brahimi and opposition MP Chokri Belaid, another prominent secular politician.

Saturday's ceremony will be attended by attended by President Moncef Marzouki, Prime Minister Ali Larayedh, parliamentary speaker Mustafa Ben Jaafar, as well as party leaders.