Tunisia's ruling Islamist party indicated Thursday it was ready to negotiate with the opposition on the formation of an apolitical government, in order to end a month-long political crisis.
The announcement of what would be a key concession that Ennahda has until now resisted came after its leader, Rachid Ghannouchi, met Houcine Abassi, the secretary general of the powerful UGTT union, which has been mediating between the rival factions.
"The Ennahda movement accepted the proposal of the UGTT as a starting point for resolving the political crisis in the country," the Islamist leader said.
"Ennahda accepted the initiative of the UGTT as the basis for the start of a national dialogue" with the opposition, Abassi said.
Tunisia was plunged into a fresh political crisis by the assassination last month of opposition MP Mohamed Brahmi, the second of its kind in six months, sparking mass protests and calls for the Islamist-led government's resignation.
The UGTT has proposed the formation of a non-partisan government, while keeping the national assembly in place and adhering to a strict timetable for adopting a new constitution and holding fresh elections.
Neither Ghannouchi nor Abassi said Ennahda would actually accept a change of government, and they declined to take questions from journalists.
"Ennahda has made a series of proposals and we are going to relay them to the opposition. If they are accepted, we will begin a national dialogue," said Abassi.
The UGTT leader is due to meet later with representatives of an opposition umbrella group, which has repeatedly ruled out talks with Ennahda while the coalition it leads remains in power, calling instead for a new administration composed of independents.
In contrast, Ennahda has refused to take part in negotiations conditioned on the cabinet's departure, instead proposing a broad-based national unity government and fresh elections in December.
The UGTT, which boasts some 500,000 members and is capable of bringing the country to a standstill, has been central to the negotiations, shuttling between the Islamists and the opposition in a bid to break the political deadlock.
The National Salvation Front, a loose coalition of opposition parties, has called for nationwide anti-government demonstrations, starting on Saturday evening outside the national assembly.
Activists and opposition MPs have been gathering there regularly over the past months, with two protests, on August 6 and 13, drawing tens of thousands of people.
Except for some clashes at the end of July, the protests have been largely peaceful, and Islamist Prime Minister Ali Larayedh warned this week against any attacks on state institutions.
The opposition accuses Ennahda of mismanaging the economy and failing to improve living standards.
The criticism is similar to that levelled against Egypt's Islamist president Mohamed Morsi by millions of protesters who took to the streets before the army overthrew him on July 3.
Ennahda has also been accused of being too soft on radical Islamists, who are blamed for murdering Brahmi and Chokri Belaid, another prominent secular politician whose assassination in February brought down the first Ennahda-led government.
The Islamists accuse the opposition of trying to repeat the events in Egypt, where an elected president was ousted in a coup that has been followed by deadly violence and the detention of Islamist leaders.