Tunisia's opposition Salvation Front called for more protests demanding an immediate departure of the Islamist-led government, Al Arabiya television reported on Thursday, citing media sources Al Arabiya reported.
The Front is reportedly preparing an official reaction to the prime minister's latest address, the sources added.
Thousands of opposition members, including leftists and union activists, took to the streets of the capital, Tunis, on Wednesday calling for the Cabinet to resign.
Differences between the country's moderate Islamists and secular opponents, over the framework of a planned national dialogue, postponed talks intended to end a political deadlock.
A leader from Tunisia's main labor union group told a local radio station the talks will take place on Friday, Al Arabiya television said.
The opposition has been waiting for a "clear commitment" by Prime Minister Ali Larayedh to quit within three weeks, as stipulated in the roadmap drawn up by mediators and agreed to by his Ennahda party, to allow a national dialogue to begin.
The prime minister has said he would step down only after a new constitution is adopted.
Mediators hope the dialogue between Tunisia's bitterly divided political factions will mark a crucial step in the country's democratic transition and end the crisis triggered by the July murder of opposition MP Mohamma Brahmi.
Under the terms of the roadmap, the talks must lead to the formation of a caretaker cabinet of technocrats within three weeks.
Negotiators will also have one month to adopt a new constitution, electoral laws and a timetable for fresh elections.