Supporters of the Ennahda ruling party during a demonstration in Tunis
alks are due to resume on the creation of a new Tunisian government, despite opposition from the ruling party.
The country has been in political crisis since the killing of opposition politician Chokri Belaid on 6 February triggered mass protests.
This led to resignations from the coalition government.
PM Hamadi Jebali wants to form an administration of technocrats, but the idea is opposed by the leader of his Islamic Ennahda party.
Mr Jebali has threatened to resign if Ennahda blocks his solution to the political crisis sparked by the assassination of Mr Belaid.
Speaking at a march in Tunis on Saturday, Ennahda's leader Rached Ghannouchi said he rejected the formation of a government of technocrats.
He called on the National Constituent Assembly (NCA) to "complete the constitution as soon as possible and thus pave the way for free and fair elections."
However, on Friday, Mr Jebali spoke of "encouraging results" from talks with party leaders on the formation of a new government.
He stressed that it was important "to find a solution for the people and for the revolution."
Tunisian media on Sunday expressed deep concern over the ongoing uncertainty.