Tens of thousands of demonstrators have marched in the Tunisian capital, Tunis, calling for the resignation of the Islamist-led government.
The rally marked a 40-day mourning period since the killing of opposition MP Mohammed Brahmi in July.
His murder, along with the shooting of another prominent leftist politician in February, have sparked mass protests.
Talks between the opposition and the ruling Ennahda party have so far failed to achieve a major breakthrough.
The moderate Islamist government has blamed Salafist hardliners for the killings of Mr Brahmi and secular opposition leader Chokri Belaid.
The opposition coalition, led by the National Salvation Front (NSF), has accused Ennahda of failing to rein in radical Islamists and improve the faltering economy.