A broad coalition of opposition parties and civil society groups organised the demonstration with an estimated turnout of more than 100,000.
Tens of thousands of people demonstrated overnight in Tunisia to demand the resignation of the Islamist-led government.
At least 40,000 people shouting slogans such as “The people want the fall of the regime” and “Get lost” attended the rally outside parliament buildings in the Tunis suburb of Bardo, authorities said.
The broad coalition of opposition parties and civil society groups that organised the demonstration estimated the turnout at more than 100,000. Many had come by bus from regional towns.
The demonstration to mark the six months that have passed since the assassination of opposition politician Chokri Belaid was the biggest in nearly two weeks of daily protests, which began after the slaying of opposition deputy Mohamed Brahmi on July 25, 2013.
The president of the assembly, Mustafa Ben Jaafar, announced late Tuesday he was suspending the assembly’s work until the government and opposition began direct talks on ending the political crisis.
Tunisia was the first Arab country to overthrow an authoritarian leader through popular protest in 2011 and to hold elections that brought an Islamist party to power.
Nearly two years after the polls the country is mired in its worst crisis since the overthrow of President Zine El Abidine Ben Ali.
The government has blamed radical Islamists for the killings of both Belaid and Brahmi.
Their families and the opposition have accused the ruling Islamist party Ennahda of having a share of responsibility.